Compounds for nonsense suppression, and methods for their use

ABSTRACT

The present invention relates to methods, compounds, and compositions for treating or preventing diseases associated with nonsense mutations in an mRNA by administering the compounds or compositions of the present invention. More particularly, the present invention relates to methods, compounds, and compositions for suppressing premature translation termination associated with a nonsense mutation in an mRNA.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 13/042,456, filed Mar. 7, 2011, which U.S. application Ser. No. 13/042,456 is a divisional of U.S. application Ser. No. 11/577,192, filed Apr. 12, 2007, which U.S. application Ser. No. 11/577,192 is a national phase application under 35 U.S.C. §371 of International Application No. PCT/US2005/037052, filed Oct. 13, 2005, which claims priority to and the benefit under 35 U.S.C. §119 of U.S. Provisional Application No. 60/617,670, filed Oct. 13, 2004, U.S. Provisional Application No. 60/617,634, filed Oct. 13, 2004, U.S. Provisional Application No. 60/617,633, filed Oct. 13, 2004, U.S. Provisional Application No. 60/617,655, filed Oct. 13, 2004, U.S. Provisional Application No. 60/617,653, filed Oct. 13, 2004, and U.S. Provisional Application No. 60/624,170, filed Nov. 3, 2004, the entire contents of all of which applications are incorporated herein by reference.

RELATED APPLICATIONS

The present application also incorporates by reference herein in their entireties International Patent Applications entitled “Compounds for Nonsense Suppression, and Methods for Their Use,” filed on Oct. 13, 2005 and identified as PCT/US05/36764, PCT/US05/36673, PCT/US05/36761, and PCT/US05/36762.

FIELD OF THE INVENTION

The present invention relates to methods, compounds, and compositions for treating or preventing diseases associated with nonsense mutations in an mRNA by administering the compounds or compositions of the present invention. More particularly, the present invention relates to methods and compounds and compositions for suppressing premature translation termination associated with a nonsense mutation in an mRNA.

BACKGROUND OF THE INVENTION

Gene expression in cells depends upon the sequential processes of transcription and translation. Together, these processes produce a protein from the nucleotide sequence of its corresponding gene.

Transcription involves the synthesis of mRNA from DNA by RNA polymerase. Transcription begins at a promoter region of the gene and continues until termination is induced, such as by the formation of a stem-loop structure in the nascent RNA or the binding of the rho gene product.

Protein is produced from mRNA by the process of translation, occurring on the ribosome with the aid of tRNA, tRNA synthetases and various other protein and RNA species. Translation comprises the three phases of initiation, elongation and termination. Translation is initiated by the formation of an initiation complex consisting of protein factors, mRNA, tRNA, cofactors and the ribosomal subunits that recognize signals on the mRNA that direct the translation machinery to begin translation on the mRNA. Once the initiation complex is formed, growth of the polypeptide chain occurs by the repetitive addition of amino acids by the peptidyl transferase activity of the ribosome as well as tRNA and tRNA synthetases. The presence of one of the three termination codons (UAA, UAG, UGA) in the A site of the ribosome signals the polypeptide chain release factors (RFs) to bind and recognize the termination signal. Subsequently, the ester bond between the 3′ nucleotide of the tRNA located in the ribosome's P site and the nascent polypeptide chain is hydrolyzed, the completed polypeptide chain is released, and the ribosome subunits are recycled for another round of translation.

Mutations of the DNA sequence in which the number of bases is altered are categorized as insertion or deletion mutations (e.g., frameshift mutations) and can result in major disruptions of the genome. Mutations of the DNA that change one base into another and result in an amino acid substitution are labeled missense mutations. Base substitutions are subdivided into the classes of transitions (one purine to another purine, or one pyrimidine to another pyrimidine) and transversions (a purine to a pyrimidine, or a pyrimidine to a purine).

Transition and transversion mutations can result in a nonsense mutation changing an amino acid codon into one of the three stop codons. These premature stop codons can produce aberrant proteins in cells as a result of premature translation termination. A nonsense mutation in an essential gene can be lethal and can also result in a number of human diseases, such as, cancers, lysosomal storage disorders, the muscular dystrophies, cystic fibrosis and hemophilia, to name a few.

The human p53 gene is the most commonly mutated gene in human cancer (Zambetti, G. P. and Levine, A., FASEB 7:855-865 (1993)). Found in both genetic and spontaneous cancers, over 50 different types of human cancers contain p53 mutations and mutations of this gene occur in 50-55% of all human cancers (Hollstein, M., et al., Nucleic Acids Res. 22:3551-55 (1994); International Agency for Research on Cancer (IARC) database). Approximately 70% of colorectal cancer, 50% of lung cancer and 40% of breast cancers contain mutant p53 (Koshland, D., Science 262:1953 (1993)). Aberrant forms of p53 are associated with poor prognosis, more aggressive tumors, metastasis, and lower 5 year survival rates (Id.). p53's role in the induction of cell growth arrest and/or apoptosis upon DNA damage is believed to be essential for the destruction of mutated cells that would have otherwise gained a growth advantage. In addition, p53 sensitizes rapidly dividing cells to apoptotic signals. Of greater than 15,000 reported mutations in the p53 gene, approximately 7% are nonsense mutations. Accordingly, there is a need for a safe and effective treatment directed to p53 nonsense mutations.

In bacterial and eukaryotic strains with nonsense mutations, suppression of the nonsense mutation can arise as a result of a mutation in one of the tRNA molecules so that the mutant tRNA can recognize the nonsense codon, as a result of mutations in proteins that are involved in the translation process, as a result of mutations in the ribosome (either the ribosomal RNA or ribosomal proteins), or by the addition of compounds known to alter the translation process (for example, cycloheximide or the aminoglycoside antibiotics). The result is that an amino acid will be incorporated into the polypeptide chain, at the site of the nonsense mutation, and translation will not prematurely terminate at the nonsense codon. The inserted amino acid will not necessarily be identical to the original amino acid of the wild-type protein, however, many amino acid substitutions do not have a gross effect on protein structure or function. Thus, a protein produced by the suppression of a nonsense mutation would be likely to possess activity close to that of the wild-type protein. This scenario provides an opportunity to treat diseases associated with nonsense mutations by avoiding premature termination of translation through suppression of the nonsense mutation.

The ability of aminoglycoside antibiotics to promote read-through of eukaryotic stop codons has attracted interest in these drugs as potential therapeutic agents in human diseases caused by nonsense mutations. One disease for which such a therapeutic strategy may be viable is classical late infantile neuronal ceroid lipofuscinosis (LINCL), a fatal childhood neurodegenerative disease with currently no effective treatment. Premature stop codon mutations in the gene CLN2 encoding the lysosomal tripeptidyl-peptidase 1 (TPP-1) are associated with disease in approximately half of children diagnosed with LINCL. The ability of the aminoglycoside gentamicin to restore TPP-1 activity in LINCL cell lines has been examined. In one patient-derived cell line that was compound heterozygous for a commonly seen nonsense mutation (Arg208Stop) and a different rare nonsense mutation, approximately 7% of normal levels of TPP-I were maximally restored with gentamicin treatment. These results suggest that pharmacological suppression of nonsense mutations by aminoglycosides or functionally similar pharmaceuticals may have therapeutic potential in LINCL (Sleat et. al., Eur. J. Ped. Neurol. 5:Suppl A 57-62 (2001)).

In cultured cells having premature stop codons in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene, treatment with aminoglycosides led to the production of full-length CFTR (Bedwell et. al., Nat. Med. 3:1280-1284 (1997); Howard et. al. Nat. Med. 2: 467-469 (1996)). In mouse models for Duchenne muscular dystrophy, gentamicin sulfate was observed to suppress translational termination at premature stop codons resulting in full-length dystrophin (Barton-Davis et. al., J. Clin. Invest. 104:375-381 (1999)). A small increase in the amount of full-length dystrophin provided protection against contraction-induced damage in the mdx mice. The amino acid inserted at the site of the nonsense codon was not determined in these studies.

Accordingly, small molecule therapeutics or prophylactics that suppress premature translation termination by mediating the misreading of the nonsense codon would be useful for the treatment of a number of diseases. The discovery of small molecule drugs, particularly orally bioavailable drugs, can lead to the introduction of a broad spectrum of selective therapeutics or prophylactics to the public which can be used against disease caused by nonsense mutations is just beginning.

Clitocine (6-Amino-5-nitro-4-(β-D-ribo-furanosylamino)pyrimidine) is a naturally occurring exocyclic amino nucleoside that was first isolated from the mushroom Clitocybe inversa (Kubo et al., Tet. Lett. 27: 4277 (1986)). The total synthesis of clitocine has also been reported. (Moss et al., J. Med. Chem. 31:786-790 (1988) and Kamikawa et al., J. Chem. Soc. Chem. Commun. 195 (1988)). Clitocine has been reported to possess insecticidal activity and cytostatic activity against leukemia cell lines (Kubo et al., Tet. Lett. 27: 4277 (1986) and Moss et al., J. Med. Chem. 31:786-790 (1988)). However, the use of clitocine as a therapeutic for diseases associated with a nonsense mutation has not been disclosed until now. Nor has anyone reported the development of an analogue or derivative of clitocine that has utility as a therapeutic for cancer or a disease associated with a nonsense mutation.

Thus, there remains a need to develop, characterize, and optimize lead molecules for the development of novel drugs for treating or preventing diseases associated with nonsense mutations of mRNA. Accordingly, it is an object of the present invention to provide such compounds.

All documents referred to herein are incorporated by reference into the present application as though fully set forth herein.

SUMMARY OF THE INVENTION

In accordance with the present invention, compounds that suppress premature translation termination associated with a nonsense mutation in mRNA have been identified, and methods for their use provided.

In one aspect of the invention, compounds of Formula (1) are provided which are useful for suppressing premature translation termination associated with a nonsense mutation in mRNA, and for treating diseases associated with nonsense mutations in mRNA:

wherein:

X is a halogen;

R is a C₁-C₈ alkyl group; a C₁-C₄ haloalkyl group; an —OR₁ group; or an amino group which is optionally substituted with one or two independently selected R₂ groups;

R₁ is a C₁-C₈ alkyl group which is optionally substituted with one or more independently selected R_(a) groups; a —R_(b) group; a pyrrolidinyl group which is optionally substituted with one or more independently selected C₁-C₄ alkyl or oxo groups; a piperidyl group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups, benzyl groups, or carboxy groups optionally substituted with one or more C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a tetrahydro-furyl group; a tetrahydro-pyranyl group; a tetrahydro-naphthyl group; or an indanyl group;

R₂ is a hydrogen, a C₁-C₆ alkyl group; a C₁-C₄ haloalkyl group; a C₁-C₄ alkoxy group; a —R_(b) group; a pyrimidinyl group; a pyridyl group; a sulfonyl group optionally substituted with an —R_(b) group; or two R₂ groups together with the amino to which they are attached form a morpholinyl group, a pyrrolidinyl group, an isoindolinyl group, or a piperazinyl group which is optionally substituted with a phenyl group;

wherein R_(a) is a halogen; a C₁-C₄ alkoxy group; a carbamoyl group which is optionally substituted with one or two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a phosphinoyl group which is optionally substituted with one or two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a morpholinyl group; a pyridyl group; or a —R_(b) group; and

wherein R_(b) is a C₆-C₈ aryl which is optionally substituted with one or more of the following, independently selected: a hydroxy, a halogen, a C₁-C₄ alkyl group, a C₁-C₄ haloalkyl group, a C₁-C₄ alkoxy group, or an amino group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups;

or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound of Formula 1.

In another aspect of the invention, methods are provided for the suppression of premature translation termination associated with a nonsense mutation, and for the prevention or treatment of diseases associated with nonsense mutations of mRNA. Such diseases include, but are not limited to, genetic diseases caused by premature translation termination associated with a nonsense mutation, such as a CNS disease, an inflammatory disease, a neurodegenerative disease, an autoimmune disease, a cardiovascular disease, or a pulmonary disease; more preferably the disease is cancer (or other proliferative diseases), amyloidosis, Alzheimer's disease, atherosclerosis, giantism, dwarfism, hypothyroidism, hyperthyroidism, cystic fibrosis, aging, obesity, Parkinson's disease, Niemann Pick's disease, familial hypercholesterolemia, retinitis pigmentosa, Marfan syndrome, lysosomal storage disorders, the muscular dystrophies, cystic fibrosis, hemophilia, or classical late infantile neuronal ceroid lipofuscinosis (LINCL).

In one embodiment, the invention is directed to methods for suppressing premature translation termination associated with a nonsense mutation in mRNA comprising administering a nonsense-suppressing amount of at least one compound of the invention to a subject in need thereof.

In yet another embodiment, methods for treating cancer, lysosomal storage disorders, a muscular dystrophy, cystic fibrosis, hemophilia, or classical late infantile neuronal ceroid lipofuscinosis are provided comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof.

These and other aspects of the invention will be more clearly understood with reference to the following embodiments, detailed description, and claims, for example.

CERTAIN EMBODIMENTS

-   1. A method of treating or preventing a disease resulting from a     somatic mutation comprising administration to a patient in need     thereof an effective amount of a compound of Formula 1:

wherein:

X is a halogen;

R is a C₁-C₈ alkyl group; a C₁-C₄ haloalkyl group; an —OR₁ group; or an amino group which is optionally substituted with one or two independently selected R₂ groups;

R₁ is a C₁-C₈ alkyl group which is optionally substituted with one or more independently selected R_(a) groups; a —R_(b) group; a pyrrolidinyl group which is optionally substituted with one or more independently selected C₁-C₄ alkyl or oxo groups; a piperidyl group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups, benzyl groups, or carboxy groups optionally substituted with one or more C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a tetrahydro-furyl group; a tetrahydro-pyranyl group; a tetrahydro-naphthyl group; or an indanyl group;

R₂ is a hydrogen, a C₁-C₆ alkyl group; a C₁-C₄ haloalkyl group; a C₁-C₄ alkoxy group; a —R_(b) group; a pyrimidinyl group; a pyridyl group; a sulfonyl group optionally substituted with an —R_(b) group; or two R₂ groups together with the amino to which they are attached form a morpholinyl group, a pyrrolidinyl group, an isoindolinyl group, or a piperazinyl group which is optionally substituted with a phenyl group;

wherein R_(a) is a halogen; a C₁-C₄ alkoxy group; a carbamoyl group which is optionally substituted with one or two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a phosphinoyl group which is optionally substituted with one or two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a morpholinyl group; a pyridyl group; or an —R_(b) group; and

wherein R_(b) is a C₆-C₈ aryl which is optionally substituted with one or more of the following, independently selected: a hydroxy, a halogen, a C₁-C₄ alkyl group, a C₁-C₄ haloalkyl group, a C₁-C₄ alkoxy group, or an amino group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups;

or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound of Formula 1.

-   2. The method of embodiment 1, wherein the compound of Formula 1, or     a pharmaceutically acceptable salt, hydrate, solvate, clathrate     polymorph, racemate or stereoisomer thereof, is administered as a     composition comprising the compound and a pharmaceutically     acceptable carrier or diluent. -   3. The method of embodiment 1, wherein the administration is     intravenous. -   4. The method of embodiment 1, wherein X is fluorine and is in an     ortho position. -   5. The method of embodiment 1, wherein the compound of Formula 1 is     a compound of Formula 1A:

-   6. The method of embodiment 5, wherein R₁ is a C₁-C₈ alkyl group     which is optionally substituted with one or more independently     selected R_(a) groups. -   7. The method of embodiment 5, wherein X is fluorine and is located     in an ortho position. -   8. The method of embodiment 1, wherein the compound of Formula 1 is     a compound of Formula 1B:

-   9. The method of embodiment 8, wherein at least one R₂ is H. -   10. The method of embodiment 8, wherein X is fluorine and is located     in an ortho position. -   11. The method of embodiment 1, wherein the compound of Formula 1 is     a compound of Formula 1C:

wherein R_(c) is independently selected from hydrogen, a halogen, a methyl, or an ethyl.

-   12. The method of embodiment 11, wherein at least one R_(c) is     fluorine. -   13. The method of embodiment 11, wherein X is fluorine and is     located in an ortho position. -   14. The method of embodiment 1, where R is a C₁-C₄ alkyl group; a     C₁-C₄ haloalkyl group; an —OR₁ group; or an amino group which is     optionally substituted with one or two independently selected R₂     groups. -   15. A method of treating or preventing an autoimmune disease, a     blood disease, a collagen disease, diabetes, a neurodegenerative     disease, a cardiovascular disease, a pulmonary disease, or an     inflammatory disease or central nervous system disease comprising     administration to a patient in need thereof an effective amount of a     compound of Formula 1, or a pharmaceutically acceptable salt,     hydrate, solvate, clathrate, racemate or stereoisomer thereof. -   16. The method of embodiment 15, wherein the administration is     intravenous. -   17. The method of embodiment 15, wherein the autoimmune disease is     rheumatoid arthritis or graft versus host disease. -   18. The method of embodiment 15, wherein the inflammatory disease is     arthritis. -   19. The method of embodiment 15, wherein the central nervous system     disease is multiple sclerosis, muscular dystrophy, Duchenne muscular     dystrophy, Alzheimer's disease, a neurodegenerative disease or     Parkinson's disease. -   20. The method of embodiment 15, wherein the blood disorder is     hemophilia, Von Willebrand disease, ataxia-telangiectasia,     β-thalassemia or kidney stones. -   21. The method of embodiment 15, wherein the collagen disease is     osteogenesis imperfecta or cirrhosis. -   22. A method of treating or preventing familial polycythemia,     immunodeficiency, kidney disease, kidney stones, heart disease,     ataxia-telangiectasia, cystic fibrosis, muscular dystrophy, familial     hypercholesterolemia, retinitis pigmentosa, amyloidosis, hemophilia,     Alzheimer's disease, Tay Sachs disease, Niemann Pick disease,     Parkinson's disease, atherosclerosis, giantism, dwarfism,     hypothyroidism, hyperthyroidism, aging, obesity, Duchenne muscular     dystrophy, epidermolysis bullosa or Marfan syndrome comprising     administration to a patient in need thereof an effective amount of a     compound of Formula 1, or a pharmaceutically acceptable salt,     hydrate, solvate, clathrate, racemate or stereoisomer thereof. -   23. The method of embodiment 22, wherein the administration is     intravenous. -   24. A method of treating or preventing cancer in a human comprising     administration to a human in need thereof an effective amount of a     compound of Formula 1, or a pharmaceutically acceptable salt,     hydrate, solvate, clathrate, racemate or stereoisomer thereof. -   25. The method of embodiment 24, wherein the administration is     intravenous. -   26. The method of embodiment 24, wherein the cancer is of the head     and neck, eye, skin, mouth, throat, esophagus, chest, bone, blood,     lung, colon, sigmoid, rectum, stomach, prostate, breast, ovaries,     kidney, liver, pancreas, brain, intestine, heart or adrenals. -   27. The method of embodiment 24, wherein the compound, or a     pharmaceutically acceptable salt, hydrate, solvate, clathrate or     stereoisomer thereof, comprises a pharmaceutically acceptable     carrier or diluent. -   28. The method of embodiment 24, wherein the cancer is a solid     tumor. -   29. The method of embodiment 24, wherein the cancer is sarcoma,     carcinoma, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma,     osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma,     lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma,     mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon     carcinoma, pancreatic cancer, breast cancer, ovarian cancer,     prostate cancer, squamous cell carcinoma, basal cell carcinoma,     adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma,     papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma,     medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma,     hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal     carcinoma, Wilms' tumor, cervical cancer, testicular tumor, lung     carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial     carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma,     ependymoma, Kaposi's sarcoma, pinealoma, hemangioblastoma, acoustic     neuroma, oligodendroglioma, menangioma, melanoma, neuroblastoma,     retinoblastoma, a blood-born tumor or multiple myeloma. -   30. The method of embodiment 24, wherein the cancer is acute     lymphoblastic leukemia, acute lymphoblastic B-cell leukemia, acute     lymphoblastic T-cell leukemia, acute myeloblastic leukemia, acute     promyelocytic leukemia, acute monoblastic leukemia, acute     erythroleukemic leukemia, acute megakaryoblastic leukemia, acute     myelomonocytic leukemia, acute nonlymphocyctic leukemia, acute     undifferentiated leukemia, chronic myelocytic leukemia, chronic     lymphocytic leukemia, hairy cell leukemia, or multiple myeloma. -   31. A method of treating or preventing a disease associated with a     mutation of the p53 gene comprising administration to a patient in     need thereof an effective amount of a compound of Formula 1, or a     pharmaceutically acceptable salt, hydrate, solvate, clathrate,     racemate or stereoisomer thereof. -   32. The method of embodiment 31, wherein the administration is     intravenous. -   33. The method of embodiment 31, wherein the disease is sarcoma,     carcinomas, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma,     osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma,     lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma,     mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon     carcinoma, pancreatic cancer, breast cancer, ovarian cancer,     prostate cancer, squamous cell carcinoma, basal cell carcinoma,     adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma,     papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma,     medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma,     hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal     carcinoma, Wilms' tumor, cervical cancer, testicular tumor, lung     carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial     carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma,     ependymoma, Kaposi's sarcoma, pinealoma, hemangioblastoma, acoustic     neuroma, oligodendroglioma, menangioma, melanoma, neuroblastoma,     retinoblastoma a blood-born tumor or multiple myeloma. -   34. A method of inhibiting the growth of a cancer cell comprising     contacting the cancer cell with an effective amount of a compound of     Formula 1, or a pharmaceutically acceptable salt, hydrate, solvate,     clathrate, polymorph, racemate or stereoisomer thereof. -   35. A method for selectively producing a protein in a mammal     comprising, transcribing a gene containing a nonsense mutation in     the mammal; and providing an effective amount of a compound of the     present invention to said mammal, wherein said protein is produced     from said gene containing a nonsense mutation. -   36. A compound of Formula 1:

wherein:

-   -   X is a halogen;     -   R is a C₁-C₈ alkyl group; a C₁-C₄ haloalkyl group; an —OR₁         group; or an amino group which is optionally substituted with         one or two independently selected R₂ groups;     -   R₁ is a C₁-C₈ alkyl group which is optionally substituted with         one or more independently selected R_(a) groups; a —R_(b) group;         a pyrrolidinyl group which is optionally substituted with one or         more independently selected C₁-C₄ alkyl or oxo groups; a         piperidyl group which is optionally substituted with one or more         independently selected C₁-C₄ alkyl groups, benzyl groups, or         carboxy groups optionally substituted with one or more C₁-C₄         alkyl or C₁-C₄ alkoxy groups; a tetrahydro-furyl group; a         tetrahydro-pyranyl group; a tetrahydro-naphthyl group; or an         indanyl group;     -   R₂ is a hydrogen, a C₁-C₆ alkyl group; a C₁-C₄ haloalkyl group;         a C₁-C₄ alkoxy group; a —R_(b) group; a pyrimidinyl group; a         pyridyl group; a sulfonyl group optionally substituted with an         —R_(b) group; or two R₂ groups together with the amino to which         they are attached form a morpholinyl group, a pyrrolidinyl         group, an isoindolinyl group, or a piperazinyl group which is         optionally substituted with a phenyl group;     -   wherein R_(a) is a halogen; a C₁-C₄ alkoxy group; a carbamoyl         group which is optionally substituted with one or two         independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a         phosphinoyl group which is optionally substituted with one or         two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a         morpholinyl group; a pyridyl group; or an —R_(b) group; and     -   wherein R_(b) is a C₆-C₈ aryl which is optionally substituted         with one or more of the following, independently selected: a         hydroxy, a halogen, a C₁-C₄ alkyl group, a C₁-C₄ haloalkyl         group, a C₁-C₄ alkoxy group, or an amino group which is         optionally substituted with one or more independently selected         C₁-C₄ alkyl groups;     -   or a pharmaceutically acceptable salt, hydrate, solvate,         clathrate, polymorph, racemate or stereoisomer of said compound         of Formula 1.

-   37. The compound of embodiment 36, where R is a C₁-C₄ alkyl group; a     C₁-C₄ haloalkyl group; an —OR₁ group; or an amino group which is     optionally substituted with one or two independently selected R₂     groups.

-   38. The compound of embodiment 36, wherein said compound is selected     from compounds 1-51.

-   39. A compound having the formula (Compound NO: 1):

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides schematic representations of constructs for luciferase based assays to evaluate the suppression of a nonsense mutation.

FIG. 2 provides schematic representations of the luciferase constructs engineered to harbor one or more epitope tags in the N-terminus of the luciferase protein.

FIG. 3 provides schematic representations of constructs for luciferase based assays to evaluate readthrough efficiency.

DETAILED DESCRIPTION OF THE INVENTION

Premature translation termination can produce aberrant proteins which can be lethal or can cause a number of diseases, including as non-limiting examples, cancers, lysosomal storage disorders, the muscular dystrophies, cystic fibrosis, and hemophilia. In accordance with the present invention, compounds that suppress nonsense mutations have been identified, and methods for their use provided.

A. Compounds of the Invention

In one aspect of the invention, compounds of the invention are provided which are useful in suppression of a nonsense mutation. Compounds of the present invention are also useful for increasing the expression of a protein. In certain embodiments, the compounds of the invention specifically suppresses a nonsense mutation, while in other embodiments, the compounds of the invention suppress a nonsense mutation as well as treat a disease, including as non-limiting examples, cancers, lysosomal storage disorders, the muscular dystrophies, cystic fibrosis and hemophilia.

Preferred compounds of the present invention useful in the suppression of a nonsense mutation include those of Formula (1) as shown below.

wherein:

X is a halogen;

R is a C₁-C₈ alkyl group; a C₁-C₄ haloalkyl group; an —OR₁ group; or an amino group which is optionally substituted with one or two independently selected R₂ groups;

R₁ is a C₁-C₈ alkyl group which is optionally substituted with one or more independently selected R_(a) groups; a —R_(b) group; a pyrrolidinyl group which is optionally substituted with one or more independently selected C₁-C₄ alkyl or oxo groups; a piperidyl group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups, benzyl groups, or carboxy groups optionally substituted with one or more C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a tetrahydro-furyl group; a tetrahydro-pyranyl group; a tetrahydro-naphthyl group; or an indanyl group;

R₂ is a hydrogen, a C₁-C₆ alkyl group; a C₁-C₄ haloalkyl group; a C₁-C₄ alkoxy group; a —R_(b) group; a pyrimidinyl group; a pyridyl group; a sulfonyl group optionally substituted with an —R_(b) group; or two R₂ groups together with the amino to which they are attached form a morpholinyl group, a pyrrolidinyl group, an isoindolinyl group, or a piperazinyl group which is optionally substituted with a phenyl group;

wherein R_(a) is a halogen; a C₁-C₄ alkoxy group; a carbamoyl group which is optionally substituted with one or two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a phosphinoyl group which is optionally substituted with one or two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a morpholinyl group; a pyridyl group; or an —R_(b) group; and

wherein R_(b) is a C₆-C₈ aryl which is optionally substituted with one or more of the following, independently selected: a hydroxy, a halogen, a C₁-C₄ alkyl group, a C₁-C₄ haloalkyl group, a C₁-C₄ alkoxy group, or an amino group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups;

or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound of Formula 1.

Preferred compounds of the present invention useful in the suppression of a nonsense mutation also include those of Formula (1) as above wherein:

X is a halogen;

R is a C₁-C₈ alkyl group; a C₁-C₄ haloalkyl group; an —OR₁ group; or an amino group which is optionally substituted with one or two independently selected R₂ groups;

R₁ is a C₁-C₈ alkyl group which is optionally substituted with one or more independently selected R_(a) groups; a —R_(b) group; a pyrrolidinyl group which is optionally substituted with one or more independently selected C₁-C₄ alkyl or oxo groups; a piperidyl group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups, benzyl groups, or carboxy groups optionally substituted with one or more C₁-C₄ alkyl; a tetrahydro-furyl group; a tetrahydro-pyranyl group; a tetrahydro-naphthyl group; or an indanyl group;

R₂ is a C₁-C₆ alkyl group; a C₁-C₄ haloalkyl group; a C₁-C₄ alkoxy group; a —R_(b) group; a pyrimidinyl group; a pyridyl group; a sulfonyl group optionally substituted with an —R_(b) group; or two R₂ groups together with the amino to which they are attached form a morpholinyl group, a pyrrolidinyl group, or an isoindolinyl group;

wherein R_(a) is a halogen; a C₁-C₄ alkoxy group; a carbamoyl group; a phosphinoyl group which is optionally substituted with one or two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups; a morpholinyl group; a pyridyl group; or a —R_(b) group; and

wherein R_(b) is a C₆-C₈ aryl which is optionally substituted with one or more of the following, independently selected: a halogen, a C₁-C₄ alkyl group, or a C₁-C₄ haloalkyl group;

or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound of Formula 1.

With respect to Formula 1, the position of X (e.g., ortho, meta, or para) on the phenyl ring is stated relative to the oxadiazole ring of Formula 1.

In an embodiment of Formula 1, X is fluorine. In another embodiment of Formula 1, X is a halogen other than fluorine. In a further embodiment of Formula 1, X is chlorine. In a further embodiment of Formula 1, X is bromine. In another embodiment of Formula 1, X is iodine.

In an embodiment of Formula 1, R is a C₁-C₈ alkyl group or a C₁-C₄ haloalkyl group. In an embodiment of Formula 1, R is a C₁-C₈ alkyl group or a C₁-C₄ haloalkyl group, and X is a halogen selected from the group consisting of fluorine, chlorine, bromine or iodine. In another embodiment of Formula 1, R is a C₁-C₈ alkyl group, or a C₁-C₄ haloalkyl group, and X is fluorine.

A variety of embodiments of compounds of Formula 1A are considered within the scope of this invention. In an embodiment of Formula 1A, R₁ is a linear or branched C₁-C₈ alkyl group. In another embodiment, R₁ is a C₃-C₈ cyclic alkyl group. In a further embodiment of Formula 1A, R₁ is a C₁-C₈ alkyl group substituted with one or more R_(a) groups, where R_(a) is an alkoxy group or a phosphinoyl group which is optionally substituted with one or two independently selected C₁-C₄ alkyl or C₁-C₄ alkoxy groups. In another embodiment of Formula 1A, R₁ is a C₁-C₄ alkyl group optionally substituted with one or more R_(a) groups, where R_(a) is a morpholinyl or a pyridinyl group. In an embodiment of Formula 1A, R₁ is selected from a tetrahydro-furyl group, a tetrahydro-pyranyl group, a tetrahydro-naphthyl group, or an indanyl group. In another embodiment of Formula 1A, R₁ is R_(b), where R_(b) is a C₆ aryl group, optionally substituted with one or more groups selected from: hydroxy, halogen, C₁-C₄ alkyl group, C₁-C₄ haloalkyl group, C₁-C₄ alkoxy group, or an amino group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups. In addition, in another embodiment of compounds of Formula 1A, R₁ is a C₁-C₄ alkyl group optionally substituted with one or more independently selected R_(a) groups, where R_(a) is an R group. In an embodiment of Formula 1A, X may be selected from the group consisting of fluorine, chlorine, bromine and iodine. In another embodiment of Formula 1A, X may be fluorine.

A variety of embodiments of compounds of Formula 1B are envisioned. For example, in an embodiment of Formula 1B, the N(R₂)₂ functionality is an amino group and both R₂ groups are hydrogen. In another embodiment of Formula 1B, neither R₂ groups is hydrogen. In an alternative embodiment of Formula 1B, only one R₂ group is hydrogen. In a further embodiment of Formula 1B, both R₂ groups, together with the amino to which they are attached, form a morpholinyl group, a pyrrolidinyl group, an isoindolinyl group, or a piperazinyl group which is optionally substituted with a phenyl group. In another embodiment of Formula 1B, one or both R₂ groups is a sulfonyl group substituted with an —R_(b) group. In a further embodiment, one R₂ is a sulfonyl group substituted with an —R_(b) group and the other R₂ group is a hydrogen.

In another embodiment of Formula 1B, at least one R₂ group can be an aromatic group. In an embodiment of Formula 1B, one R₂ group is a hydrogen and the other R₂ group is a pyrimidinyl group or a pyridyl group. In yet another embodiment of compounds of Formula 1B, one R₂ group is a hydrogen and the other R₂ group is an —R_(b) group. In addition, compounds of Formula 1B include compounds where one R₂ is a hydrogen and the other is an R_(b) group, wherein the R_(b) group is a C₆ aryl group optionally substituted with one or more substituents independently selected from: hydroxy, halogen, C₁-C₄ alkyl, C₁-C₄ haloalkyl, C₁-C₄ alkoxy, or an amino group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups. In another embodiment, compounds of Formula 1B include compounds where one R₂ is a hydrogen and the other is an R_(b) group, wherein the R_(b) group is a phenyl group optionally substituted with one or more substituents independently selected from: hydroxy, halogen, C₁-C₄ alkyl, C₁-C₄ haloalkyl, C₁-C₄ alkoxy, or an amino group which is optionally substituted with one or more independently selected C₁-C₄ alkyl groups. In an embodiment of Formula 1B, X may be selected from the group consisting of fluorine, chlorine, bromine and iodine. In another embodiment of Formula 1B, X may be fluorine.

A variety of embodiments of compounds of Formula 1C are considered within the scope of this invention. By way of non-limiting example, in an embodiment, three R_(c) groups of Formula 1C are hydrogen. In another embodiment, one R_(c) group is hydrogen and the other two R_(c) groups are methyl. In yet another embodiment, two R_(c) groups are hydrogen and the remaining R_(c) group is a methyl or an ethyl group. In an embodiment of Formula 1C, X may be selected from the group consisting of fluorine, chlorine, bromine and iodine. In another embodiment of Formula 1C, X may be fluorine.

As recognized by one of skill in the art, certain compounds of the invention may include at least one chiral center, and as such may exist as racemic mixtures or as enantiomerically pure compositions. As used herein, “enantiomerically pure” refers to compositions consisting substantially of a single isomer, preferably consisting of 90%, 92%, 95%, 98%, 99%, or 100% of a single isomer.

As used herein, the term “alkyl” generally refers to saturated hydrocarbonyl radicals of straight, branched or cyclic configuration including methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, octyl, n-octyl, and the like. In some embodiments, alkyl substituents may be C₁ to C₈, C₁ to C₆, or C₁ to C₄ alkyl groups. In certain embodiments, the alkyl group may be optionally substituted with one or more halogen or alkoxy groups. For instance, the alkyl group may be a haloalkyl, including monohaloalkyl, dihaloalkyl, and trihaloalkyl.

As used herein, “alkylene” generally refers to linear, branched or cyclic alkene radicals having one or more carbon-carbon double bonds, such as C₂ to C₆ alkylene groups including 3-propenyl.

As used herein, “aryl” refers to a carbocyclic aromatic ring structure. Included in the scope of aryl groups are aromatic rings having from five to twenty carbon atoms. Aryl ring structures include compounds having one or more ring structures, such as mono-, bi-, or tricyclic compounds. Non-limiting examples of aryl groups include phenyl, tolyl, anthracenyl, fluorenyl, indenyl, azulenyl, phenanthrenyl (i.e., phenanthrene), and napthyl (i.e., napthalene) ring structures. In certain embodiments, the aryl group may be optionally substituted.

As used herein, “heterocycle” refers to cyclic ring structures in which one or more atoms in the ring, the heteroatom(s), is an element other than carbon. Heteroatoms are typically O, S or N atoms. Included within the scope of heterocycle, and independently selectable, are O, N, and S heterocycle ring structures. The ring structure may include compounds having one or more ring structures, such as mono-, bi-, or tricyclic compounds, and may be aromatic, i.e., the ring structure may be a heteroaryl. Example of heterocyclo groups include morpholinyl, pyrrolidinonyl, pyrrolidinyl, piperidinyl, piperazinyl, hydantoinyl, valerolactamyl, oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydropyridinyl, tetrahydroprimidinyl, tetrahydrothiophenyl or tetrahydrothiopyranyl and the like. In certain embodiments, the heterocycle may optionally be substituted.

As used herein, “heteroaryl” refers to cyclic aromatic ring structures in which one or more atoms in the ring, the heteroatom(s), is an element other than carbon. Heteroatoms are typically O, S or N atoms. Included within the scope of heteroaryl, and independently selectable, are O, N, and S heteroaryl ring structures. The ring structure may include compounds having one or more ring structures, such as mono-, bi-, or tricyclic compounds. In some embodiments, the heteroaryl groups may be selected from heteroaryl groups that contain two or more heteroatoms, three or more heteroatoms, or four or more heteroatoms. Heteroaryl ring structures may be selected from those that contain five or more atoms, six or more atoms, or eight or more atoms. In a preferred embodiment, a heteroaryl includes five to ten atoms. Examples of heteroaryl ring structures include: acridine, benzimidazole, benzoxazole, benzodioxole, benzofuran, 1,3-diazine, 1,2-diazine, 1,2-diazole, 1,4-diazanaphthalene, furan, furazan, imidazole, indole, isoxazole, isoquinoline, isothiazole, oxazole, purine, pyridazine, pyrazole, pyridine, pyrazine, pyrimidine, pyrrole, quinoline, quinoxaline, thiazole, thiophene, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole and quinazoline.

As used herein, “alkoxy” generally refers to a group with the structure —O—R. In certain embodiments, R may be an alkyl group, such as a C₁ to C₈, C₁ to C₆ alkyl group, or C₁ to C₄ alkyl group. In certain embodiments, the R group of the alkoxy may optionally be substituted with at least one halogen. For example, the R group of the alkoxy may be a haloalkyl, i.e., haloalkoxy.

Halogen substituents may be independently selected from the halogens such as fluorine, chlorine, bromine, iodine, and astatine.

For the purposes of this invention, where one or more functionalities or substituents are incorporated into a compound of the invention, including preferred embodiments, each functionality or substituent appearing at any location within the disclosed compounds may be independently selected, and as appropriate, independently substituted. Further, where a more generic substituent is set forth for any position in the molecules of the present invention, it is understood that the generic substituent may be replaced with more specific substituents, and the resulting molecules are within the scope of the molecules of the present invention.

With reference to Formula 1, X is preferably fluorine and is preferably in an ortho position. Preferred R₁ groups include those shown in the table below.

Preferred R₁ Groups

Preferred R₂ groups include those shown in the table below.

Preferred R₂ Groups H

Also with reference to Formula 1, preferred R groups include those shown in the table below.

Preferred R Groups

CH₃

In a preferred embodiment, compounds of Formula 1 include the compounds of Formula 1-A:

With reference to Formula 1-A, R₁ is preferably a C₁-C₈ alkyl group optionally substituted with one or more independently selected R_(a) groups. Further, X is preferably fluorine and is preferably located in an ortho position.

In another preferred embodiment, compounds of Formula 1 include the compounds of Formula 1-B:

With reference to Formula 1-B, at least one R₂ group is preferably a hydrogen. Further, X is preferably fluorine and is preferably located in an ortho position.

In yet another preferred embodiment, compounds of Formula 1 include the compounds of Formula 1-C:

With reference to Formula 1-C, R_(c) is independently selected from hydrogen, a halogen, a methyl, or an ethyl. At least one R_(c) group is preferably a fluorine. Further, X is preferably fluorine and is preferably located in an ortho position.

Preferred compounds of the invention include the following.

Compound

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

The above compounds are listed only to provide examples that may be used in the methods of the invention. Based upon the instant disclosure, the skilled artisan would recognize other compounds intended to be included within the scope of the presently claimed invention that would be useful in the methods recited herein.

B. Preparation of Compounds of the Invention

Compounds of the invention may be produced in any manner known in the art. By way of example, compounds of the invention may be prepared according to the following general schemes with reference to the individual R group structures. For example, triazine compounds of Formulas 1-A, 1-B, and 1-C may be prepared in the manner shown in the following Scheme A.

In certain preferred embodiments, compounds of the invention may be resolved to enantiomerically pure compositions or synthesized as enantiomerically pure compositions using any method known in art. By way of example, compounds of the invention may be resolved by direct crystallization of enantiomer mixtures, by diastereomer salt formation of enantiomers, by the formation and separation of diasteriomers or by enzymatic resolution of a racemic mixture.

These and other reaction methodologies may be useful in preparing the compounds of the invention, as recognized by one of skill in the art. Various modifications to the above schemes and procedures will be apparent to one of skill in the art, and the invention is not limited specifically by the method of preparing the compounds of the invention.

C. Methods of the Invention

In another aspect of the invention, methods are provided for the suppression of premature translation termination, which may be associated with a nonsense mutation, and for the prevention or treatment of diseases. In a preferred embodiment, such diseases are associated with mutations of mRNA, especially nonsense mutations. Exemplary diseases include, but are not limited to, cancer, lysosomal storage disorders, the muscular dystrophies, cystic fibrosis, hemophilia, epidermolysis bullosa, and classical late infantile neuronal ceroid lipofuscinosis. In an embodiment, methods for treating cancer, lysosomal storage disorders, the muscular dystrophies, cystic fibrosis, hemophilia, epidermolysis bullosa, and classical late infantile neuronal ceroid lipofuscinosis are provided comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof. In another embodiment, methods for treating cancer, lysosomal storage disorders, a muscular dystrophy, cystic fibrosis, hemophilia, or classical late infantile neuronal ceroid lipofuscinosis are provided comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof.

In one embodiment, the present invention is directed to methods for increasing the expression of one or more specific, functional proteins. Any compound of the invention can be used to specifically increase expression of functional protein. In another embodiment, a specific increase in expression of functional protein occurs when premature translation termination is suppressed by administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof.

In a preferred embodiment premature translation termination is associated with a nonsense mutation in mRNA. In another embodiment, a specific increase in expression of functional protein occurs when mRNA decay is reduced in a patient. In a preferred embodiment, the abnormality in a patient is caused by mutation-mediated mRNA decay.

In a particularly preferred embodiment, mutation-mediated mRNA decay is the result of a nonsense mutation. The methods of the present invention are not limited by any particular theory.

The invention encompasses methods of treating and preventing diseases or disorders ameliorated by the suppression of premature translation termination, nonsense-mediated mRNA decay, or premature translation termination and nonsense-mediated mRNA decay in a patient which comprise administering to a patient in need of such treatment or prevention a therapeutically effective amount of one or more compounds of the invention.

In an embodiment, the present invention encompasses the treatment or prevention of any disease that is associated with a gene exhibiting premature translation termination, nonsense-mediated mRNA decay, or premature translation termination and nonsense-mediated mRNA decay. In one embodiment, the disease is due, in part, to a lack of or a reduced expression of the gene resulting from a premature stop codon. Specific examples of genes which may exhibit premature translation termination and/or nonsense-mediated mRNA decay and diseases associated with premature translation termination and/or nonsense-mediated mRNA decay are found in U.S. Provisional Patent Application No. 60/390,747, titled: Methods For Identifying Small Molecules That Modulate Premature Translation Termination And Nonsense Mediated mRNA Decay, filed Jun. 21, 2002, and International Application PCT/US03/19760, filed Jun. 23, 2003, both of which are incorporated herein by reference in their entireties.

Diseases ameliorated by the suppression of premature translation termination, nonsense-mediated mRNA decay, or premature translation termination and nonsense-mediated mRNA decay include, but are not limited to: genetic diseases, somatic diseases, cancers, autoimmune diseases, blood diseases, collagen diseases, diabetes, neurodegenerative diseases, proliferative diseases, cardiovascular diseases, pulmonary diseases, inflammatory diseases, or central nervous system diseases.

In one embodiment, diseases to be treated or prevented by administering to a patient in need thereof an effective amount of a compound of the invention include, but are not limited to, amyloidosis, hemophilia, Alzheimer's disease, Tay Sachs disease, Niemann Pick disease, atherosclerosis, giantism, dwarfism, hypothyroidism, hyperthyroidism, aging, obesity, Parkinson's disease, cystic fibrosis, muscular dystrophy, heart disease, kidney stones, ataxia-telangiectasia, familial hypercholesterolemia, retinitis pigmentosa, Duchenne muscular dystrophy, epidermolysis bullosa and Marfan syndrome. In one embodiment, the diseases are associated with a nonsense mutation.

In one embodiment, the compounds of the invention are useful for treating or preventing an autoimmune disease. In one embodiment, the autoimmune disease is associated with a nonsense mutation. In a preferred embodiment, the autoimmune disease is rheumatoid arthritis or graft versus host disease.

In another embodiment, the compounds of the invention are useful for treating or preventing a blood disease. In one embodiment, the blood disease is associated with a nonsense mutation. In a preferred embodiment, the blood disease is hemophilia, Von Willebrand disease, β-thalassemia or kidney stones.

In another embodiment, the compounds of the invention are useful for treating or preventing a collagen disease. In one embodiment, the collagen disease is associated with a nonsense mutation. In a preferred embodiment, the collagen disease is osteogenesis imperfecta or cirrhosis.

In another embodiment, the compounds of the invention are useful for treating or preventing diabetes. In one embodiment, the diabetes is associated with a nonsense mutation.

In another embodiment, the compounds of the invention are useful for treating or preventing an inflammatory disease. In one embodiment, the inflammatory disease is associated with a nonsense mutation. In a preferred embodiment, the inflammatory disease is arthritis, rheumatoid arthritis or osteoarthritis.

In another embodiment, the compounds of the invention are useful for treating or preventing a central nervous system disease. In one embodiment, the central nervous system disease is associated with a nonsense mutation. In one embodiment, the central nervous system disease is a neurodegenerative disease. In a preferred embodiment, the central nervous system disease is multiple sclerosis, muscular dystrophy, Duchenne muscular dystrophy, Alzheimer's disease, Tay Sachs disease, Niemann Pick disease, late infantile neuronal ceroid lipofuscinosis (LINCL) or Parkinson's disease.

In another preferred embodiment, the compounds of the invention are useful for treating or preventing cancer, particularly in humans. In a preferred embodiment, the cancer is of the head and neck, eye, skin, mouth, throat, esophagus, chest, bone, blood, lung, colon, sigmoid, rectum, stomach, prostate, breast, ovaries, kidney, liver, pancreas, brain, intestine, heart or adrenals. In one embodiment, the cancer is a solid tumor. In one embodiment, the cancer is associated with a nonsense mutation. In another embodiment, the cancer is associated with a genetic nonsense mutation. In another embodiment, the cancer is associated with a somatic mutation. Without being limited by any theory, the use of the compounds of the invention against cancer may relate to its action against mutations of the p53 gene.

In one embodiment, the cancer is not a blood cancer. In another embodiment, the cancer is not leukemia. In another embodiment, the cancer is not multiple myeloma. In another embodiment, the cancer is not prostate cancer.

In another preferred embodiment, the compounds of the invention are useful for treating or preventing cancer associated with a mutation of tumor suppressor gene. Such genes include, but are not limited to, PTEN, BRCA1, BRCA2, Rb, and the p53 gene. In one embodiment, the mutation is a genetic mutation. In another embodiment, the mutation is a somatic mutation. The methods of the invention are particularly useful for treating or preventing a cancer associated with a nonsense mutation in the in a tumor suppressor gene. In a preferred embodiment, the methods of the invention are particularly useful for treating or preventing a cancer associated with a p53 gene due to the role of p53 in apoptosis. Without being limited by theory, it is thought that apoptosis can be induced by contacting a cell with an effective amount of a compound of the invention resulting in suppression of the nonsense mutation, which, in turn, allows the production of full-length p53 to occur. Nonsense mutations have been identified in the p53 gene and have been implicated in cancer. Several nonsense mutations in the p53 gene have been identified (see, e.g., Masuda et al., 2000, Tokai J Exp Clin Med. 25(2):69-77; Oh et al., 2000, Mol Cells 10(3):275-80; Li et al., 2000, Lab Invest. 80(4):493-9; Yang et al., 1999, Zhonghua Zhong Liu Za Zhi 21(2):114-8; Finkelstein et al., 1998, Mol Diagn. 3(1):37-41; Kajiyama et al., 1998, Dis Esophagus. 11(4):279-83; Kawamura et al., 1999, Leuk Res. 23(2):115-26; Radig et al., 1998, Hum Pathol. 29(11):1310-6; Schuyer et al., 1998, Int J Cancer 76(3):299-303; Wang-Gohrke et al., 1998, Oncol Rep. 5(1):65-8; Fulop et al., 1998, J Reprod Med. 43(2):119-27; Ninomiya et al., 1997, J Dermatol Sci. 14(3):173-8; Hsieh et al., 1996, Cancer Lett. 100(1-2):107-13; Rall et al., 1996, Pancreas. 12(1):10-7; Fukutomi et al., 1995, Nippon Rinsho. 53(11):2764-8; Frebourg et al., 1995, Am J Hum Genet. 56(3):608-15; Dove et al., 1995, Cancer Surv. 25:335-55; Adamson et al., 1995, Br J Haematol. 89(1):61-6; Grayson et al., 1994, Am J Pediatr Hematol Oncol. 16(4):341-7; Lepelley et al., 1994, Leukemia. 8(8):1342-9; McIntyre et al., 1994, J Clin Oncol. 12(5):925-30; Horio et al., 1994, Oncogene. 9(4):1231-5; Nakamura et al., 1992, Jpn J Cancer Res. 83(12):1293-8; Davidoff et al., 1992, Oncogene. 7(1):127-33; and Ishioka et al., 1991, Biochem Biophys Res Commun. 177(3):901-6; the disclosures of which are hereby incorporated by reference herein in their entireties). Any disease associated with a p53 gene encoding a premature translation codon including, but not limited to, the nonsense mutations described in the references cited above, may be treated or prevented by compounds of the invention.

In other embodiments, diseases to be treated or prevented by administering to a patient in need thereof an effective amount of a compound of the invention include, but are not limited to, solid tumors such as sarcoma, carcinomas, fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, testicular tumor, lung carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, Kaposi's sarcoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, menangioma, melanoma, neuroblastoma, retinoblastoma, a blood-born tumor or multiple myeloma.

In another embodiment, diseases to be treated or prevented by administering to a patient in need thereof an effective amount of a compound of the invention include, but are not limited to, a blood-born tumor such as acute lymphoblastic leukemia, acute lymphoblastic B-cell leukemia, acute lymphoblastic T-cell leukemia, acute myeloblastic leukemia, acute promyelocytic leukemia, acute monoblastic leukemia, acute erythroleukemic leukemia, acute megakaryoblastic leukemia, acute myelomonocytic leukemia, acute nonlymphocyctic leukemia, acute undifferentiated leukemia, chronic myelocytic leukemia, chronic lymphocytic leukemia, hairy cell leukemia, or multiple myeloma. See e.g., Harrison's Principles of Internal Medicine, Eugene Braunwald et al., eds., pp. 491-762 (15th ed. 2001).

In yet another embodiment, the invention encompasses the treatment of a human afflicted with a solid tumor or a blood tumor.

In a preferred embodiment, the invention encompasses a method of treating or preventing a disease ameliorated by modulation of premature translation termination, nonsense-mediated mRNA decay, or premature translation termination and nonsense-mediated mRNA decay, or ameliorating one or more symptoms associated therewith comprising contacting a cell with a therapeutically effective amount of a compound of the invention. Cells encompassed by the present methods include animal cells, mammalian cells, bacterial cells, and virally infected cells. In one embodiment, the nonsense mutation is a genetic mutation (i.e., the nonsense codon was present in the progenitor DNA). In another embodiment, the nonsense mutation is a somatic mutation (i.e., the nonsense codon arose spontaneously or from mutagenesis).

In certain embodiments, a compound of the invention is administered to a subject, including but not limited to a plant, reptile, avian, amphibian or preferably a mammal, more preferably a human, as a preventative measure against a disease associated with premature translation termination, nonsense-mediated mRNA decay, or premature translation termination and nonsense-mediated mRNA decay.

In a preferred embodiment, it is first determined that the patient is suffering from a disease associated with premature translation termination and/or nonsense-mediated mRNA decay. In another embodiment, the patient has undergone a screening process to determine the presence of a nonsense mutation comprising the steps of screening a subject, or cells extracted therefrom, by an acceptable nonsense mutation screening assay. In a preferred embodiment, the DNA of the patient can be sequenced or subjected to Southern Blot, polymerase chain reaction (PCR), use of the Short Tandem Repeat (STR), or polymorphic length restriction fragments (RFLP) analysis to determine if a nonsense mutation is present in the DNA of the patient. In one embodiment, it is determined whether the nonsense mutation is a genetic mutation or a somatic mutation by comparison of progenitor DNA. Alternatively, it can be determined if altered levels of the protein with the nonsense mutation are expressed in the patient by Western blot or other immunoassays. In another embodiment, the patient is an unborn child who has undergone screening in utero for the presence of a nonsense mutation. Administration of a compound of the invention can occur either before or after birth. In a related embodiment, the therapy is personalized in that the patient is screened for a nonsense mutation screening assay and treated by the administration of one or more compounds of the invention; particularly, the patient may be treated with a compound particularly suited for the mutations in question; e.g., depending upon the disease type, cell type, and the gene in question. Such methods are well known to one of skill in the art.

In another embodiment, the cells (e.g., animal cells, mammalian cells, bacterial cells, plant cells and virally infected cells) are screened for premature translation termination and/or nonsense-mediated mRNA decay with a method such as that described above (i.e., the DNA of the cell can be sequenced or subjected to Southern Blot, polymerase chain reaction (PCR), use of the Short Tandem Repeat (STR), or polymorphic length restriction fragments (RFLP) analysis to determine if a nonsense mutation is present in the DNA of the cell; the RNA of the cell can be subjected to quantitative real time PCR to determine transcript abundance).

Specific methods of the invention further comprise the administration of an additional therapeutic agent (i.e., a therapeutic agent other than a compound of the invention). In certain embodiments of the present invention, the compounds of the invention can be used in combination with at least one other therapeutic agent. Therapeutic agents include, but are not limited to: non-opioid analgesics; non-steroid anti-inflammatory agents; steroids, antimimetics; β-adrenergic blockers; anticonvulsants; antidepressants; Ca²⁺-channel blockers; anticancer agent(s); antibiotics; and mixtures thereof.

In certain embodiments, the compounds of the invention can be administered or formulated in combination with anticancer agents. Suitable anticancer agents include, but are not limited to: alkylating agents; nitrogen mustards; folate antagonists; purine antagonists; pyrimidine antagoinists; spindle poisons; topoisomerase inhibitors; apoptosis inducing agents; angiogenesis inhibitors; podophyllotoxins; nitrosoureas; cisplatin; carboplatin; interferon; asparginase; tamoxifen; leuprolide; flutamide; megestrol; mitomycin; bleomycin; doxorubicin; irinotecan; and taxol.

In certain embodiments, the compounds of the invention can be administered or formulated in combination with antibiotics. In certain embodiments, the antibiotic is an aminoglycoside (e.g., tobramycin), a cephalosporin (e.g., cephalexin, cephradine, cefuroxime, cefprozil, cefaclor, cefixime or cefadroxil), a clarithromycin (e.g., clarithromycin), a macrolide (e.g., erythromycin), a penicillin (e.g., penicillin V) or a quinolone (e.g., ofloxacin, ciprofloxacin or norfloxacin). In a preferred embodiment, the antibiotic is active against Pseudomonas aeruginosa.

Without intending to be limited by theory, it is believed that the methods of the present invention act through a combination of mechanisms that suppress nonsense mutations. In preferred embodiments, the methods of the invention comprise administering a therapeutically effective amount of at least one compound of the invention, e.g., a compound of Formula 1. Relative activity of the compounds of the invention may be determined by any method known in the art, including for example, the assay described in Example 2 herein.

Compounds of the invention can be characterized with an in vitro luciferase nonsense suppression assay. Luciferase assays are included in the methods of the present invention. Luciferase can be used as a functional reporter gene assay (light is only produced if the protein is functional), and luciferase is extremely sensitive (light intensity is proportional to luciferase concentration in the nM range). In one embodiment, an assay of the present invention is a cell-based luciferase reporter assay. In a preferred cell-based luciferase reporter assay, a luciferase reporter construct containing a premature termination codon (UGA, UAA, or UAG) is stably transfected in 293 Human Embryonic Kidney cells.

In another assay of the present invention, a preferred assay is a biochemical assay consisting of rabbit reticulocyte lysate and a nonsense-containing luciferase reporter mRNA. In another assay of the present invention, the assay is a biochemical assay consisting of prepared and optimized cell extract (Lie & Macdonald, 1999, Development 126(22):4989-4996 and Lie & Macdonald, 2000, Biochem. Biophys. Res. Commun. 270(2):473-481. In the biochemical assay, mRNA containing a premature termination codon (UGA, UAA, or UAG) is used as a reporter in an in vitro translation reaction using rabbit reticulocyte lysate supplemented with tRNA, hemin, creatine kinase, amino acids, KOAc, Mg(OAc)₂, and creatine phosphate. Translation of the mRNA is initiated within a virus derived leader sequence, which significantly reduces the cost of the assay because capped RNA is not required. Synthetic mRNA is prepared in vitro using the T7 promoter and the MegaScript in vitro transcription kit (Ambion, Inc.; Austin, Tex.). In assays of the present invention, addition of gentamicin, an aminoglycoside known to allow readthrough of premature termination codons, results in increased luciferase activity and can be used as an internal standard. Assays of the present invention can be used in high-throughput screens. Hundreds of thousands of compounds can be screened in cell-based and biochemical assays of the present invention. In a preferred aspect, a functional cell-based assay similar to the one described is provided.

Compounds of the present invention include compounds capable of increasing specific, functional protein expression from mRNA molecules comprising premature termination codons. In one embodiment, compounds of the present invention can preferentially suppress premature translation termination. For example, a compound of the present invention can be capable of suppressing a nonsense mutation if the mutation results in UAA, but not capable of suppressing a nonsense mutation if the mutation results in UAG. Another non-limiting example occurs when a compound of the present invention is capable of suppressing a nonsense mutation if the mutation results in UAA and is followed, in-frame by a cytosine at the +1 position, but the same compound of the invention is not capable of suppressing a nonsense mutation if the mutation results in UAA and is followed, in-frame by an adenine at the +1 position.

A stable cell line harboring the UGA nonsense-containing luciferase gene can be treated with a test compound. In this aspect, cells can be grown in standard medium supplemented with 1% penicillin-streptomycin (P/S) and 10% fetal bovine serum (FBS) to 70% confluency and split 1:1 the day before treatment. The next day, cells are trypsinized and 40,000 cells are added to each well of a 96-well tissue culture dish. Serial dilutions of each compound are prepared to generate a six-point dose response curve spanning 2 logs (30 μM to 0.3 μM). The final concentration of the DMSO solvent remains constant at 1% in each well. Cells treated with 1% DMSO serve as the background standard, and cells treated with gentamicin serve as a positive control.

To address the effects of the nonsense-suppressing compounds on mRNAs altered in specific inherited diseases, a bronchial epithelial cell line harboring a nonsense codon at amino acid 1282 (W1282X) can be treated with a compound of the invention and CFTR function is monitored as a cAMP-activated chloride channel using the SPQ assay (Yang et al., Hum. Mol. Genet. 2(8):1253-1261 (1993) and Howard et al., Nat. Med. 2(4):467-469 (1996)). The increase in SPQ fluorescence in cells treated with a compound of the invention is compared to those treated with cAMP and untreated cells. An increase in SPQ fluorescence in cells is consistent with stimulation of CFTR-mediated halide efflux and an increase in readthrough of the nonsense codon. Full-length CFTR expression from this nonsense-containing allele following treatment with a compound of the invention demonstrates that cystic fibrosis cell lines increase chloride channel activity when treated with a compound of the invention.

D. Metabolites of the Compounds of the Invention

Also falling within the scope of the present invention are the in vivo metabolic products of the compounds described herein. Such products may result for example from the oxidation, reduction, hydrolysis, amidation, esterification and the like of the administered compound, primarily due to enzymatic processes. Accordingly, the invention includes compounds produced by a process comprising contacting a compound of this invention with a mammalian tissue or a mammal for a period of time sufficient to yield a metabolic product thereof. Such products typically are identified by preparing a radio-labeled (e.g. ¹⁴C or ³H) compound of the invention, administering it in a detectable dose (e.g., greater than about 0.5 mg/kg) to a mammal such as rat, mouse, guinea pig, monkey, or to man, allowing sufficient time for metabolism to occur (typically about 30 seconds to about 30 hours), and isolating its conversion products from urine, blood or other biological samples. These products are easily isolated since they are labeled (others are isolated by the use of antibodies capable of binding epitopes surviving in the metabolite). The metabolite structures are determined in conventional fashion, e.g., by MS or NMR analysis. In general, analysis of metabolites may be done in the same way as conventional drug metabolism studies well-known to those skilled in the art. The conversion products, so long as they are not otherwise found in vivo, are useful in diagnostic assays for therapeutic dosing of the compounds of the invention even if they possess no biological activity of their own.

E. Pharmaceutical Compositions of the Invention

While it is possible for the compounds of the present invention to be administered neat, it may be preferable to formulate the compounds as pharmaceutical compositions. As such, in yet another aspect of the invention, pharmaceutical compositions useful in the methods of the invention are provided. The pharmaceutical compositions of the present invention may be formulated with pharmaceutically acceptable excipients such as carriers, solvents, stabilizers, adjuvants, diluents, etc., depending upon the particular mode of administration and dosage form. The pharmaceutical compositions should generally be formulated to achieve a physiologically compatible pH, and may range from a pH of about 3 to a pH of about 11, preferably about pH 3 to about pH 7, or about pH 4 to about pH 7, depending on the formulation and route of administration. In an alternative embodiment, it may be preferred that the pH is adjusted to a range from about pH 5 to about pH 8.

More particularly, the pharmaceutical compositions of the invention comprise a therapeutically or prophylactically effective amount of at least one compound of the present invention, together with one or more pharmaceutically acceptable excipients. Optionally, the pharmaceutical compositions of the invention may comprise a combination of compounds of the present invention, or may include a second active ingredient useful in the treatment of cancer, diabetic retinopathy, or exudative macular degeneration.

Formulations of the present invention, e.g., for parenteral or oral administration, are most typically solids, liquid solutions, emulsions or suspensions, while inhaleable formulations for pulmonary administration are generally liquids or powders, with powder formulations being generally preferred. A preferred pharmaceutical composition of the invention may also be formulated as a lyophilized solid that is reconstituted with a physiologically compatible solvent prior to administration. Alternative pharmaceutical compositions of the invention may be formulated as syrups, creams, ointments, tablets, and the like.

The pharmaceutical compositions of the invention can be administered to the subject via any drug delivery route known in the art. Specific exemplary administration routes include oral, ocular, rectal, buccal, topical, nasal, ophthalmic, subcutaneous, intramuscular, intraveneous (bolus and infusion), intracerebral, transdermal, and pulmonary.

The term “pharmaceutically acceptable excipient” refers to an excipient for administration of a pharmaceutical agent, such as the compounds of the present invention. The term refers to any pharmaceutical excipient that may be administered without undue toxicity. Pharmaceutically acceptable excipients are determined in part by the particular composition being administered, as well as by the particular method used to administer the composition. Accordingly, there exists a wide variety of suitable formulations of pharmaceutical compositions of the present invention (see, e.g., Remington's Pharmaceutical Sciences, 18th Ed., Mack Publishing Co, 1990).

Suitable excipients may be carrier molecules that include large, slowly metabolized macromolecules such as proteins, polysaccharides, polylactic acids, polyglycolic acids, polymeric amino acids, amino acid copolymers, and inactive virus particles. Other exemplary excipients include antioxidants such as ascorbic acid; chelating agents such as EDTA; carbohydrates such as dextrin, hydroxyalkylcellulose, hydroxyalkylmethylcellulose, stearic acid; liquids such as oils, water, saline, glycerol and ethanol; wetting or emulsifying agents; pH buffering substances; and the like. Liposomes are also included as exemplary pharmaceutically acceptable excipients.

The pharmaceutical compositions of the invention may be formulated in any form suitable for the intended method of administration. When intended for oral use for example, tablets, troches, lozenges, aqueous or oil suspensions, non-aqueous solutions, dispersible powders or granules (including micronized particles or nanoparticles), emulsions, hard or soft capsules, syrups or elixirs may be prepared. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions, and such compositions may contain one or more agents including sweetening agents, flavoring agents, coloring agents and preserving agents, in order to provide a palatable preparation.

Pharmaceutically acceptable excipients particularly suitable for use in conjunction with tablets include, for example, inert diluents, such as celluloses, calcium or sodium carbonate, lactose, calcium or sodium phosphate; disintegrating agents, such as croscarmellose sodium, cross-linked povidone, maize starch, or alginic acid; binding agents, such as povidone, starch, gelatin or acacia; and lubricating agents, such as magnesium stearate, stearic acid or talc. Tablets may be uncoated or may be coated by known techniques including microencapsulation to delay disintegration and adsorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate alone or with a wax may be employed.

Formulations for oral use may be also presented as hard gelatin capsules where the active ingredient is mixed with an inert solid diluent, for example celluloses, lactose, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with non-aqueous or oil medium, such as glycerin, propylene glycol, polyethylene glycol, peanut oil, liquid paraffin or olive oil.

In another embodiment, pharmaceutical compositions of the invention may be formulated as suspensions comprising a compound of the present invention in admixture with at least one pharmaceutically acceptable excipient suitable for the manufacture of a suspension. In yet another embodiment, pharmaceutical compositions of the invention may be formulated as dispersible powders and granules suitable for preparation of a suspension by the addition of suitable excipients.

Excipients suitable for use in connection with suspensions include suspending agents, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropyl methylcelluose, sodium alginate, polyvinylpyrrolidone, gum tragacanth, gum acacia, dispersing or wetting agents such as a naturally occurring phosphatide (e.g., lecithin), a condensation product of an alkylene oxide with a fatty acid (e.g., polyoxyethylene stearate), a condensation product of ethylene oxide with a long chain aliphatic alcohol (e.g., heptadecaethyleneoxycethanol), a condensation product of ethylene oxide with a partial ester derived from a fatty acid and a hexitol anhydride (e.g., polyoxyethylene sorbitan monooleate); and thickening agents, such as carbomer, beeswax, hard paraffin or cetyl alcohol. The suspensions may also contain one or more preservatives such as acetic acid, methyl and/or n-propyl p-hydroxy-benzoate; one or more coloring agents; one or more flavoring agents; and one or more sweetening agents such as sucrose or saccharin.

The pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, such as olive oil or arachis oil, a mineral oil, such as liquid paraffin, or a mixture of oils. Suitable emulsifying agents include naturally-occurring gums, such as gum acacia and gum tragacanth; naturally occurring phosphatides, such as soybean lecithin, esters or partial esters derived from fatty acids; hexitol anhydrides, such as sorbitan monooleate; and condensation products of these partial esters with ethylene oxide, such as polyoxyethylene sorbitan monooleate. The emulsion may also contain sweetening and flavoring agents. Syrups and elixirs may be formulated with sweetening agents, such as glycerol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative, a flavoring or a coloring agent.

Additionally, the pharmaceutical compositions of the invention may be in the form of a sterile injectable preparation, such as a sterile injectable aqueous emulsion or oleaginous suspension. This emulsion or suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, such as a solution in 1,2-propane diol. The sterile injectable preparation may also be prepared as a lyophilized powder. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile fixed oils may be employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid may likewise be used in the preparation of injectables.

Generally, the compounds of the present invention useful in the methods of the present invention are substantially insoluble in water and are sparingly soluble in most pharmaceutically acceptable protic solvents and in vegetable oils. However, the compounds are generally soluble in medium chain fatty acids (e.g., caprylic and capric acids) or triglycerides and have high solubility in propylene glycol esters of medium chain fatty acids. Also contemplated in the invention are compounds which have been modified by substitutions or additions of chemical or biochemical moieties which make them more suitable for delivery (e.g., increase solubility, bioactivity, palatability, decrease adverse reactions, etc.), for example by esterification, glycosylation, PEGylation, etc.

In a preferred embodiment, the compounds of the present invention may be formulated for oral administration in a lipid-based formulation suitable for low solubility compounds. Lipid-based formulations can generally enhance the oral bioavailability of such compounds. As such, a preferred pharmaceutical composition of the invention comprises a therapeutically or prophylactically effective amount of a compound of the present invention, together with at least one pharmaceutically acceptable excipient selected from the group consisting of: medium chain fatty acids or propylene glycol esters thereof (e.g., propylene glycol esters of edible fatty acids such as caprylic and capric fatty acids) and pharmaceutically acceptable surfactants such as polyoxyl 40 hydrogenated castor oil.

In an alternative preferred embodiment, cyclodextrins may be added as aqueous solubility enhancers. Preferred cyclodextrins include hydroxypropyl, hydroxyethyl, glucosyl, maltosyl and maltotriosyl derivatives of α-, β-, and γ-cyclodextrin. A particularly preferred cyclodextrin solubility enhancer is hydroxypropyl-β-cyclodextrin (HPBC), which may be added to any of the above-described compositions to further improve the aqueous solubility characteristics of the compounds of the present invention. In one embodiment, the composition comprises 0.1% to 20% hydroxypropyl-β-cyclodextrin, more preferably 1% to 15% hydroxypropyl-β-cyclodextrin, and even more preferably from 2.5% to 10% hydroxypropyl-β-cyclodextrin. The amount of solubility enhancer employed will depend on the amount of the compound of the present invention in the composition.

A therapeutically effective amount, as used herein, refers to an amount of a pharmaceutical composition of the invention to treat, ameliorate, or modulate an identified disease or condition, or to exhibit a detectable therapeutic or inhibitory effect. The effect can be detected by, for example, assays of the present invention. The effect can also be the prevention of a disease or condition where the disease or condition is predicted for an individual or a high percentage of a population.

The precise effective amount for a subject will depend upon a variety of factors such as for example the subject's body weight, size, and health; the nature and extent of the condition; the therapeutic or combination of therapeutics selected for administration, the protein half-life, the mRNA half-life and the protein localization. Therapeutically effective amounts for a given subject can be determined by routine experimentation that is within the skill and judgment of the clinician.

For any compound, the therapeutically effective amount can be estimated initially either in cell culture assays, e.g., of neoplastic cells, or in animal models, usually rats, mice, rabbits, dogs, or pigs. The animal model may also be used to determine the appropriate concentration range and route of administration. Such information can then be used to determine useful doses and routes for administration in humans. Therapeutic/prophylactic efficacy and toxicity may be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., ED₅₀ (the dose therapeutically effective in 50% of the population) and LD₅₀ (the dose lethal to 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index, and it can be expressed as the ratio, LD50/ED50. Pharmaceutical compositions that exhibit large therapeutic indices are preferred. The data obtained from cell culture assays and animal studies may be used in formulating a range of dosage for human use. The dosage contained in such compositions is preferably within a range of circulating concentrations that include an ED₅₀ with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed, sensitivity of the patient, and the route of administration.

More specifically, the concentration-biological effect relationships observed with regard to the compound(s) of the present invention indicate an initial target plasma concentration ranging from approximately 5 μg/mL to approximately 100 μg/mL, preferably from approximately 10 μg/mL to approximately 50 μg/mL, more preferably from approximately 10 μg/mL to approximately 25 μg/mL. To achieve such plasma concentrations, the compounds of the invention may be administered at doses that vary from 1 mg/kg to 150 mg/kg, depending upon the route of administration. Guidance as to particular dosages and methods of delivery is provided in the literature and is generally available to practitioners in the art. In general the dose will be in the range of about 1 mg/day to about 10 g/day, or about 0.1 g to about 3 g/day, or about 0.3 g to about 3 g/day, or about 0.5 g to about 2 g/day, in single, divided, or continuous doses for a patient weighing between about 40 to about 100 kg (which dose may be adjusted for patients above or below this weight range, particularly children under 40 kg).

The magnitude of a prophylactic or therapeutic dose of a particular active ingredient of the invention in the acute or chronic management of a disease or condition will vary, however, with the nature and severity of the disease or condition, and the route by which the active ingredient is administered. The dose, and perhaps the dose frequency, will also vary according to the age, body weight, and response of the individual patient. Suitable dosing regimens can be readily selected by those skilled in the art with due consideration of such factors. In general, the recommended daily dose range for the conditions described herein lie within the range of from about 1 mg/kg to about 150 mg/kg per day. In one embodiment, the compound of the invention is given as a single once-a-day dose. In another embodiment, the compound of the invention is given as divided doses throughout a day. More specifically, the daily dose is administered in a single dose or in equally divided doses. Preferably, a daily dose range should be from about 5 mg/kg to about 100 mg/kg per day, more preferably, between about 10 mg/kg and about 90 mg/kg per day, even more preferably 20 mg/kg to 60 mg/kg per day. In managing a patient, the therapy should be initiated at a lower dose, perhaps about 200 mg to about 300 mg, and increased if necessary up to about 600 mg to about 4000 mg per day as either a single dose or divided doses, depending on the patient's global response. It may be necessary to use dosages of the active ingredient outside the ranges disclosed herein in some cases, as will be apparent to those of ordinary skill in the art. Furthermore, it is noted that the clinician or treating physician will know how and when to interrupt, adjust, or terminate therapy in conjunction with individual patient response.

Different therapeutically effective amounts may be applicable for different diseases and conditions, as will be readily known by those of ordinary skill in the art. Similarly, amounts sufficient to treat or prevent such diseases, but insufficient to cause, or sufficient to reduce, adverse effects associated with conventional therapies are also encompassed by the above described dosage amounts and dose frequency schedules.

As stated before, the exact dosage will be determined by the practitioner, in light of factors related to the subject that requires treatment. Dosage and administration are adjusted to provide sufficient levels of the active agent(s) or to maintain the desired effect. Factors which may be taken into account include the severity of the disease state, general health of the subject, age, weight, and gender of the subject, diet, time, protein of interest half-life, RNA of interest half-life, frequency of administration, drug combination(s), reaction sensitivities, and tolerance/response to therapy. Long-acting pharmaceutical compositions may be administered every 3 to 4 days, every week, or once every two weeks depending on half-life and clearance rate of the particular formulation.

F. Combination Therapy

It is also possible to combine one or more compounds of the present invention with one or more other active ingredients useful in the treatment of diseases associated with nonsense mutations of mRNA as described herein, including compounds in a unitary dosage form, or in separate dosage forms intended for simultaneous or sequential administration to a patient in need of treatment. When administered sequentially, the combination may be administered in two or more administrations. In an alternative embodiment, it is possible to administer one or more compounds of the present invention and one or more additional active ingredients by different routes.

The skilled artisan will recognize that a variety of active ingredients may be administered in combination with the compounds of the present invention that may act to augment or synergistically enhance the nonsense mutation-suppressing activity of the compounds of the invention.

According to the methods of the invention, the combination of active ingredients may be: (1) co-formulated and administered or delivered simultaneously in a combined formulation; (2) delivered by alternation or in parallel as separate formulations; or (3) by any other combination therapy regimen known in the art. When delivered in alternation therapy, the methods of the invention may comprise administering or delivering the active ingredients sequentially, e.g., in separate solution, emulsion, suspension, tablets, pills or capsules, or by different injections in separate syringes. In general, during alternation therapy, an effective dosage of each active ingredient is administered sequentially, i.e., serially, whereas in simultaneous therapy, effective dosages of two or more active ingredients are administered together. Various sequences of intermittent combination therapy may also be used.

G. Gene Therapy

The compounds of the present invention or other nonsense compounds can be utilized in combination with gene therapy. In this embodiment, a gene can be introduced or provided to a mammal, preferably a human that contains a specified nonsense mutation in the desired gene. In a preferred aspect, the desired gene is selected from the group consisting of IGF1, EPO, p53, p19ARF, p21, PTEN, EI 24 and ApoAI. In order to obtain expression of the full-length polypeptide in a patient or mammal, the patient or mammal would be provided with an effective amount of a compound of the present invention or other nonsense suppression compound when such polypeptide is desired.

There are typically two major approaches to getting nucleic acids that contain a nonsense mutation (optionally contained in a vector) into a patient's cells: in vivo and ex vivo. For in vivo delivery the nucleic acid is injected directly into the patient, usually at the sites where the polypeptide is required, i.e., the site of synthesis of the polypeptide, if known, and the site (e.g. solid tumor) where biological activity of the polypeptide is needed. For ex vivo treatment, the patient's cells are removed, the nucleic acid is introduced into the isolated cells, and the modified cells are administered to the patient either directly or, for example, encapsulated within porous membranes that are implanted into the patient (see e.g., U.S. Pat. Nos. 4,892,538 and 5,283,187). There are a variety of techniques available for introducing nucleic acids into viable cells. The techniques vary depending upon whether the nucleic acid is transferred into cultured cells in vitro, or transferred in vivo in the cells of the intended host. Techniques suitable for the transfer of nucleic acid into mammalian cells in vitro include the use of liposomes, electroporation, microinjection, transduction, cell fusion, DEAE-dextran, the calcium phosphate precipitation method, etc. Transduction involves the association of a replication-defective, recombinant viral (preferably retroviral) particle with a cellular receptor, followed by introduction of the nucleic acids contained by the particle into the cell. A commonly used vector for ex vivo delivery of the gene is a retrovirus.

The currently preferred in vive nucleic and transfer techniques include transfection with viral or non-viral vectors (such as adenovirus, lentivirus, Herpes simplex I virus, or adeno-associated virus (AAV)) and lipid-based systems (useful lipids for lipid-mediated transfer of the gene are, for example, DOTMA, DOPE, and DC-Chol; see, e.g., Tonkinson et al., Cancer Investigation, 14 (1): 54-65 (1996)). The most preferred vectors for use in gene therapy are viruses, most preferably adenoviruses, AAV, lentiviruses, or retroviruses. A viral vector such as a retroviral vector includes at least one transcriptional promoter/enhancer or locus-defining element(s), or other elements that control gene expression by other means such as alternate splicing, nuclear RNA export, or post-translational modification of messenger. In addition, a viral vector such as a retroviral vector includes a nucleic acid sequence that, when transcribed with a gene encoding a polypeptide, is operably linked to the coding sequence and acts as a translation initiation sequence. Such vector constructs also include a packaging signal, long terminal repeats (LTRs) or portions thereof, and positive and negative strand primer binding sites appropriate to the virus used (if these are not already present in the viral vector). In addition, such vector typically includes a signal sequence for secretion of the polypeptide from a host cell in which it is placed. Preferably the signal sequence for this purpose is a mammalian signal sequence, most preferably the native signal sequence for the polypeptide. Optionally, the vector construct may also include a signal that directs polyadenylation, as well as one or more restriction sites and a translation termination sequences. By way of example, such vectors will typically include a 5′ LTR, a tRNA binding site, a packaging signal, a origin of second-strand DNA synthesis, and a 3′ LTR or a portion thereof. Other vectors can be used that are non-viral, such as cationic lipids, polylysine, and dendrimers.

In some situations, it is desirable to provide the nucleic acid source with an agent that targets the target cells, such as an antibody specific for a cell-surface membrane protein or the target cell, a ligand for a receptor on the target cell, etc. Where liposomes are employed, proteins that bind to a cell-surface membrane protein associated with endocytosis may be used for targeting and/or to facilitate uptake, e.g., capsid proteins or fragments thereof tropic for a particular cell type, antibodies for proteins that undergo internalization in cycling, and proteins that target intracellular localization and enhance intracellular half-life. The technique of receptor-mediated endocytosis is described, for example, by Wu et al., J. Biol. Chem. 262: 4429-4432 (1987); and Wagner et al., Proc. Natl. Acad. Sci. USA, 87: 3410-3414 (1990). For a review of the currently known gene marking and gene therapy protocols, see, Anderson et al., Science 256: 808-813 (1992). See also WO 93/25673 and the references cited therein.

Suitable gene therapy and methods for making retroviral particles and structural proteins can be found in, e.g. U.S. Pat. Nos. 5,681,746; 6,800,604 and 6,800,731.

To assist in understanding the present invention, the following Examples are included. The experiments relating to this invention should not, of course, be construed as specifically limiting the invention and such variations of the invention, now known or later developed, which would be within the purview of one skilled in the art are considered to fall within the scope of the invention as described herein and hereinafter claimed.

EXAMPLES

The present invention is described in more detail with reference to the following non-limiting examples, which are offered to more fully illustrate the invention, but are not to be construed as limiting the scope thereof. The examples illustrate the preparation of certain compounds of the invention, and the testing of these compounds in vitro and/or in vivo. Those of skill in the art will understand that the techniques described in these examples represent techniques described by the inventors to function well in the practice of the invention, and as such constitute preferred modes for the practice thereof. However, it should be appreciated that those of skill in the art should in light of the present disclosure, appreciate that many changes can be made in the specific methods that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

Example 1 Preparation of Compounds of the Invention A. Compound 25: Morpholine-4-carboxylic acid 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoylamide

Compound 25 of the present invention may be prepared according to Scheme A as follows. A slurry of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoic acid (Compound A1, 15.0 g; 52.8 mmol) and 100 μL of dimethylformamide catalyst in 250 mL of anhydrous dichloromethane is allowed to cool to 0° C. Oxalyl chloride (9.2 mL, 105.5 mmol, 2.0 eq.) is added to this slurry over 3 minutes. The reaction mixture is then allowed to warm to room temperature, and is stirred for 16 h. The resultant yellow solution is concentrated in vacuo, azeotroped several times with anhydrous dichloromethane (2×50 mL) and dried under high vacuum for 2 hrs to give 15.5 g of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoyl chloride (Compound A2) as a white solid (97%): ¹H NMR (CDCl₃) δ 7.23-7.38 (m, 2H), 7.58-7.71 (m, 2H), 8.22-8.29 (m, 2H), 8.50 (d, J=7.8 Hz, 1H), 8.91 (t, J=1.6 Hz, 1H).

Saturated NH₃/THF solution (130 ml) cooled to 0° C. via cannula slowly over 10 min is then added to a suspension of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]-benzoyl chloride (Compound A2, 8.0 g, 26.43 mmol) in anhydrous tetrahydrofuran (80 mL) cooled to −78° C. The mixture is stirred for 30 minutes, warmed to room temperature and stirred for 16 h. The solvent is concentrated in vacuo and the resulting white residue is washed several times with water. The wet solid is dried in a vacuum oven for two days to give 7.06 g (94%) of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzamide (Compound A3) as a white solid: mp 231-234° C.; ¹H NMR (300 MHz, DMSO-d₆) δ 6.10 (br d, J=9.7 Hz, 2H) 7.28-7.39 (m, 2H), 7.64 (t, J=7.8 Hz, 2H), 8.07 (d, J=7.8 Hz, 1H), 8.24 (t, J=7.5 Hz, 1H), 8.37 (d, J=7.5 Hz, 1H), 8.58 (t, J=1.8 Hz, 1H); MS m/z 284.12, calcd for C₁₅H₁₀FN₃O₂ (MH⁺) 284.

Oxalyl chloride (2.5 ml, 28.2 mmol, 2.0 eq.) is then added dropwise under N₂ to a suspension of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzamide (Compound A3, 4.0 g, 14.1 mmol) in anhydrous dichloromethane (20 mL) cooled to 0° C. The mixture is slowly heated to reflux and stirred for an additional 6 h. The solvent is removed on a rotary evaporator. The residue is azeotroped with anhydrous dichloromethane (20 mL) and dried under high vacuum for two hours to give 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoyl isocyanate (Compound A4) as a tan solid 4.12 g (95%) which may be used immediately without further purification.

Morpholine (114 μL; 1.30 mmol, 2.0 eq.) is added to a solution of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoyl isocyanate (Compound A4, 200 mg, 0.65 mmol) in anhydrous dichloromethane (4.0 mL) under nitrogen, and the reaction mixture is heated to reflux for 18 h. The resulting slurry is filtered and recrystallized from the minimum amount of dichloromethane in hexanes to afford 249 mg (97%) of morpholine-4-carboxylic acid 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoylamide (Compound 25) as a white powder: mp 190-194° C.; ¹H NMR (300 MHz, DMSO-d₆) δ 3.05 (t, J=5.1 Hz, 2H), 3.46 (d, J=4.5 Hz, 2H), 3.61 (m, 2H), 3.76 (t, J=5.1 Hz, 2H), 7.46-7.90 (m, 4H), 7.59 (d, J=8.1 Hz, 1H), 8.22-8.29 (m, 2H), 8.53 (d, J=1.5 Hz, 1 H), 9.20 (br s, 1H); MS m/z 397.15, calcd for C₂₀H₁₇FN₄O₄ (MH⁺) 397.

B. Compound 37: (±)-{3-[5-(2-Fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoyl}carbamic acid 1,2,2-trimethylpropyl ester

3,3-dimethyl-2-butanol (306 μL; 2.43 mmol, 5.0 eq.) is added to a solution of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzoyl isocyanate (Compound A4, 150 mg; 0.49 mmol) in anhydrous dichloromethane (4.0 mL) in 1-portion, and then the reaction mixture is heated to reflux for 18 h. The crude residue is purified by silica gel chromatography using a 10 g SiO₂ column (eluted with 35% ethyl acetate/hexane) to give 140 mg (70% yield) of a white powder (Compound 37): mp 170-173; ¹H NMR (300 MHz, DMSO-d₆) δ 0.92 (s, 9H), 1.17 (d, J=6.6 Hz, 3H), 4.60 (q, J=6.6 Hz, 1H), 7.46-7.85 (m, 4H), 8.07 (d, J=7.8 Hz, 1H), 8.23-8.30 (m, 2H), 8.49 (s, 1H), 11.08 (s, 1H); MS m/z 412.13, calcd for C₂₂H₂₂FN₃O₄ (MH⁺) 412.

C. Compound 45: N-Acetyl-3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzamide

Acetyl chloride (0.029 mL, 0.41 mmol, 1.17 equiv.) is added to a solution of 3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]-N-benzamide (Compound A3, 100 mg, 0.35 mmol) in anhydrous tetrahydrofuran (2 mL) and anhydrous pyridine (0.057 mL, 0.705 mmol, 2.00 equiv.) at room temperature with stirring, followed by heating of the mixture to 76° C. for 48 h. The reaction mixture is cooled to room temperature, concentrated on a rotary evaporator, and azeotroped once with toluene (2 mL portion). The solid is dissolved in dichloromethane (5 mL), washed with water, dried over MgSO₄ and concentrated to give the crude product as a solid. The product is purified by flash chromatography over a 10 g SiO₂ column (eluted with 5% ethyl acetate/dichloromethane) to give 0.061 g (49% yield) of N-Acetyl-3-[5-(2-fluorophenyl)-[1,2,4]oxadiazol-3-yl]benzamide (Compound 45) as a white solid: mp 119-120° C.; ¹H NMR (300 MHz, CDCl₃) δ 2.66 (s, 3H), 7.25-7.39 (m, 2 H), 7.60-7.71 (m, 2H), 8.05 (d, J=7.8 Hz, 1H), 8.22 (t, J=7.2 Hz, 1H), 8.43 (d, J=7.8 Hz, 1H), 8.61 (s, 1H), 8.69 (br s, 1H); MS m/z 326.25, calcd for C₁₇H₁₂FN₃O₃ (MH⁺) 326.

D: Compound 47: 2-[5-(2-Fluorophenyl)-[1,2,4]oxadiazol-3-yl]-N-(2,2,2-trifluoroacetyl)benzamide

2-[5-(2-Fluorophenyl)-[1,2,4]oxadiazol-3-yl]-N-(2,2,2-trifluoroacetyl)benzamide (Compound 52) may be prepared following the same general procedure as Example C above, except trifluoroacetic anhydride is used in place of acetyl chloride: mp 119-120° C.; ¹H NMR (300 MHz, CDCl₃) δ 7.26-7.39 (m, 2H), 7.62-7.67 (m, 2H), 7.81 (d, J=7.8 Hz, 1H), 8.21 (t, J=7.5 Hz, 1H), 8.42 (d, J=8.1 Hz, 1H), 8.49 (s, 1H); MS m/z 361.22 (M−F)⁺ calcd for C₁₇H₉F₄N₃O₃ (MH⁺) 379.

E: Compound 46: 3-[5-(2-Fluorophenyl)-[1,2,4]oxadiazol-3-yl]-N-isobutyryl-benzamide (3)

3-[5-(2-Fluorophenyl)[1,2,4]oxadiazol-3-yl]-N-isobutyrylbenzamide (Compound 46) may be prepared following the same general procedure as Example C, except isobutyryl chloride is used in place of acetyl chloride: mp 183-184° C.; ¹H NMR (300 MHz, CDCl₃) δ 1.29 (d, J=6.6 Hz, 6H), 3.67 (m, 1 H), 7.29-7.40 (m, 2H), 7.61-7.71 (m, 2H), 8.06 (d, J=7.8 Hz, 1H), 8.26 (t, J=7.8 Hz, 1H), 8.43 (d, J=7.8 Hz, 1H), 8.53 (br s, 1H), 8.62 (s, 1H); MS m/z 354.26, calcd for C₁₉H₁₆FN₃O₃ (MH⁺) 354.

Melting point and mass spectrometry (mass spec) data for certain preferred compounds of the invention are presented in the table below.

Melting Mass Spec Compound Point ° C. Data (ES+) 1 176-177 342.16 2 160.5-162  356.2 3 172-174 370.23 4  226-227.5 367.23 5 206-207 357.18 6 240 327.17 7 233-234 373.23 8 247-249 405.18 9 252-254 404.23 10 252-254 404.16 11 177.5-179  412.20 12 223-224 441.35 13 NT 478.18 14 NT 425.25 15 188-191 481.21 16 129-130 432.17 17 172-174 410.16 18 134-138 424.19 19 133-134 418.13 20 152-155 370.17 21 139-141 386.11 22 187-190 396.18 23 199-202 458.19 24 178-180 381.14 25 190-194 397.15 26 161-163 383.18 27 247-250 431.17 28 169-173 472.22 29 NT 429.33 30 140-141 430.12 (ES−) 31 150-152 396.13 32 168-170 456.17 (M − H) 33 164-165 486.13 34 141-143 400.15 35 197-200 398.1 36 165-168 442.12 (M − H) 37 170-173 412.3 38 168-170 398.29 39 108-109 412.3 40 161-163 500.24 41 NT 511.33 42 132-134 501.32 43 120-123 439.29 44 193-196 399.21 45 119-120 326.25 46 183-184 354.26 47 119-120 361.22 48 180-183 433.2 49 152-156 398.23 50 NT 398.23 51 116-118 448.23 (M − H)

Example 2 Nonsense Suppression Activity

A functional, cell-based translation assay based on luciferase-mediated chemoluminescence (International Application PCT/US2003/023185, filed on Jul. 23, 2003, hereby incorporated by reference in its entirety) permits quantitative assessment of the level of nonsense suppression. Human embryonic kidney cells (293 cells) are grown in medium containing fetal bovine serum (FBS). These cells can be stably transfected with the luciferase gene containing a premature termination codon at amino acid position 190. In place of the threonine codon (ACA) normally present in the luciferase gene at this site, each of the 3 possible nonsense codons (TAA, TAG, or TGA) and each of the 4 possible nucleotides (adenine, thymine, cytosine, or guanine) at the contextually important downstream +1 position following the nonsense codon are introduced by site-directed mutagenesis. As such, amino acid 190 in the luciferase gene containing a premature termination codon is TAA, TAG, or TGA. For each stop codon, the nucleotide following amino acid 190 of luciferase gene containing a premature termination codon can be replaced with an adenine, thymine, cytosine, or guanine (A, T, C, G) such that these mutations do not change the reading frame of the luciferase gene. Schematics of these constructs are depicted in FIG. 1.

The nonsense suppression activity from a cell-based luciferase reporter assay of the present invention as described above shown in the table below (Table 2). Human Embryonic Kidney 293 cells are stably transfected with a luciferase reporter construct comprising a UGA nonsense mutation at position 190, which is followed, in-frame by an adenine nucleotide (UGAA).

Activity measurements in Table 2 are determined in a cell-based luciferase reporter assay of the present invention using a construct containing a UGA premature termination codon. Gentamicin, an aminoglycoside antibiotic known to allow readthrough of premature termination codons, is used as an internal standard. Activity measurements are based on the qualitative ratio between the minimum concentration of compound required to produce a given protein in a cell versus the amount of protein produced by the cell at that concentration. Compounds which are found to have either or both very high potency and very high efficacy of protein synthesis are classified as “*****”. Compounds which are found to have intermediate potency and/or efficacy of protein synthesis are classified as “****”; “***”; or “**”. Similarly, compounds which are found to have lower potency and/or efficacy of protein synthesis are classified as “*”.

TABLE 2 Compound UGAA activity 1 ** 2 ** 3 *** 4 * 5 ** 6 * 7 * 8 * 9 * 10 ** 11 *** 12 ** 13 *** 14 ** 15 * 16 ** 17 ** 18 ** 19 *** 20 ** 21 *** 22 *** 23 ** 24 * 25 ** 26 ** 27 *** 28 * 29 * 30 ** 31 ** 32 ** 33 ** 34 ** 35 ** 36 ** 37 ** 38 ** 39 ** 40 ** 41 ** 42 *** 43 **** 44 **** 45 *** 46 ** 47 ** 48 *** 49 **** 50 **** 51 ***

Nonsense suppression activity in an assay as described above is shown in Table 3 below, for a construct with a UAG nonsense mutation at position 190, followed by an adenine nucleotide in-frame, (UAGA); and a construct with a UAA nonsense mutation at position 190, followed by an adenine nucleotide in-frame, (UAAA).

TABLE 3 Compound No. UAGA activity UAAA activity 43 ** ** 44 ** ** 49 ** ** 50 ** **

Example 3 Readthrough Assay

A functional, cell-based translation assay based on luciferase-mediated chemoluminescence (International Application PCT/US2003/023185, filed on Jul. 23, 2003 and incorporated by reference in its entirety) permits assessment of translation-readthough of the normal stop codon in an mRNA. Human embryonic kidney cells (293 cells) are grown in medium containing fetal bovine serum (FBS). These cells are stably transfected with the luciferase gene containing a premature termination codon at amino acid position 190. In place of the threonine codon (ACA) normally present in the luciferase gene at this site, each of the 3 possible nonsense codons (TAA, TAG, or TGA) and each of the 4 possible nucleotides (adenine, thymine, cytosine, or guanine) at the contextually important downstream +1 position following the nonsense codon are introduced by site-directed mutagenesis. As such, amino acid 190 in the luciferase gene containing a premature termination codon is TAA, TAG, or TGA. For each stop codon, the nucleotide following amino acid 190 of luciferase gene containing a premature termination codon is replaced with an adenine, thymine, cytosine, or guanine (A, T, C, G) such that these mutation do not change the reading frame of the luciferase gene. Schematics of these constructs are depicted above in FIG. 1.

Another assay of the present invention can evaluate compounds that promote nonsense mutation suppression. The luciferase constructs described above in FIG. 1 are engineered to harbor two epitope tags in the N-terminus of the luciferase protein. Based on luciferase protein production, these constructs qualitatively assess the level of translation-readthrough. The presence of the full-length luciferase protein produced by suppression of the premature termination codon is measured by immunoprecipitation of the suppressed luciferase protein (using an antibody against a His tag) followed by Western blotting using an antibody against the second epitope (the Xpress™ epitope; Invitrogen®; Carlsbad, Calif.). These constructs are depicted in FIG. 2.

Cells that harbor the constructs of FIG. 2 show increased full-length protein production when treated with a compound of the present invention. After treatment for 20 hours, cells containing the constructs of FIG. 2 are collected and an antibody recognizing the His epitope is used to immunoprecipitate the luciferase protein. Following immunoprecipitation, Western blotting is performed using the antibody to the Xpress™ epitope (Invitrogen®; Carlsbad, Calif.) to detect the truncated luciferase (produced when no nonsense suppression occurs) and to detect the full-length protein (produced by suppression of the nonsense codon). Treatment of cells with a test compound produces full-length protein and not a readthrough protein (See e.g., FIG. 3). The readthrough protein is produced if suppression of the normal termination codon occurs. Compounds of the present invention suppress the premature, i.e. nonsense mutation, but not the normal termination codon in the luciferase mRNA.

Compounds of the present invention selectively act on premature termination codons but not normal termination codons in mammals.

Rats and dogs are administered high doses of compound (up to 1800 mg/kg) by gavage (oral) once daily for 14 days. After the treatment, tissues are collected, lysates are prepared, and Western blot analysis is performed. Selection of the proteins for evaluation of normal termination codon readthrough is based primarily on the corresponding mRNA having a second stop codon in the 3′-UTR that is in-frame with the normal termination codon. Between these 2 stop codons, each selected protein has an intervening sequence of nucleotides that codes for an extension of the protein in the event of ribosomal readthrough of the first termination codon. If the compound has the capacity to induce nonspecific, ribosomal readthrough, an elongated protein is differentiated from the wild-type protein using Western blot. Tissues are collected from rats and are analyzed for suppression of the normal termination codon (UAA) in the vimentin mRNA. No evidence of suppression is apparent. Tissues are collected from dogs treated with compounds of the present invention. There is no evidence of suppression of the normal termination codon of beta actin, which harbors a UAG stop codon.

In healthy human volunteers, a single dose of a compound of the present invention (200 mg/kg) is administered orally. Blood samples are collected, plasma is prepared, and a Western blot is conducted using plasma samples from female and male subjects. C-reactive protein (CRP), which harbors a UGA termination codon, is used to determine if treatment of subjects with compounds of the present invention result in suppression of the normal termination codon in the CRP mRNA. A luciferase assay in combination with a premature termination assay demonstrates selective suppression of premature termination codons but not normal termination codons.

Example 4 Animal Models

Animal model systems can also be used to demonstrate the safety and efficacy of a compound of the present invention. The compounds of the present invention are tested for biological activity using animal models for a disease, condition, or syndrome of interest. These include animals engineered to contain the target RNA element coupled to a functional readout system, such as a transgenic mouse.

Cystic Fibrosis

Examples of animal models for cystic fibrosis include, but are not limited to, cftr(−/−) mice (see, e.g., Freedman et al., 2001, Gastroenterology 121(4):950-7), cftr(tm1HGU/tm1HGU) mice (see, e.g., Bernhard et al., 2001, Exp Lung Res 27(4):349-66), CFTR-deficient mice with defective cAMP-mediated Cl(−) conductance (see, e.g., Stotland et al., 2000, Pediatr Pulmonol 30(5):413-24), and C57BL6-Cftr(m1UNC)/Cftr(m1UNC) knockout mice (see, e.g., Stotland et al., 2000, Pediatr Pulmonol 30(5):413-24).

Muscular Dystrophy

Examples of animal models for muscular dystrophy include, but are not limited to, mouse, hamster, cat, dog, and C. elegans. Examples of mouse models for muscular dystrophy include, but are not limited to, the dy−/− mouse (see, e.g., Connolly et al., 2002, J Neuroimmunol 127(1-2):80-7), a muscular dystrophy with myositis (mdm) mouse mutation (see, e.g., Garvey et al., 2002, Genomics 79(2):146-9), the mdx mouse (see, e.g., Nakamura et al., 2001, Neuromuscul Disord 11(3):251-9), the utrophin-dystrophin knockout (dko) mouse (see, e.g., Nakamura et al., 2001, Neuromuscul Disord 11(3):251-9), the dy/dy mouse (see, e.g., Dubowitz et al., 2000, Neuromuscul Disord 10(4-5):292-8), the mdx(Cv3) mouse model (see, e.g., Pillers et al., 1999, Laryngoscope 109(8):1310-2), and the myotonic ADR-MDX mutant mice (see, e.g., Kramer et al., 1998, Neuromuscul Disord 8(8):542-50). Examples of hamster models for muscular dystrophy include, but are not limited to, sarcoglycan-deficient hamsters (see, e.g., Nakamura et al., 2001, Am J Physiol Cell Physiol 281(2):C690-9) and the BIO 14.6 dystrophic hamster (see, e.g., Schlenker & Burbach, 1991, J Appl Physiol 71(5):1655-62). An example of a feline model for muscular dystrophy includes, but is not limited to, the hypertrophic feline muscular dystrophy model (see, e.g., Gaschen & Burgunder, 2001, Acta Neuropathol (Berl) 101(6):591-600). Canine models for muscular dystrophy include, but are not limited to, golden retriever muscular dystrophy (see, e.g., Fletcher et al., 2001, Neuromuscul Disord 11(3):239-43) and canine X-linked muscular dystrophy (see, e.g., Valentine et al., 1992, Am J Med Genet 42(3):352-6). Examples of C. elegans models for muscular dystrophy are described in Chamberlain & Benian, 2000, Curr Biol 10(21):R795-7 and Culette & Sattelle, 2000, Hum Mol Genet 9(6):869-77.

Familial Hypercholesterolemia

Examples of animal models for familial hypercholesterolemia include, but are not limited to, mice lacking functional LDL receptor genes (see, e.g., Aji et al., 1997, Circulation 95(2):430-7), Yoshida rats (see, e.g., Fantappie et al., 1992, Life Sci 50(24):1913-24), the JCR:LA-cp rat (see, e.g., Richardson et al., 1998, Atherosclerosis 138(1):135-46), swine (see, e.g., Hasler-Rapacz et al., 1998, Am J Med Genet 76(5):379-86), and the Watanabe heritable hyperlipidaemic rabbit (see, e.g., Tsutsumi et al., 2000, Arzneimittelforschung 50(2):118-21; Harsch et al., 1998, Br J Pharmacol 124(2):227-82; and Tanaka et al., 1995, Atherosclerosis 114(1):73-82).

Human Cancer

An example of an animal model for human cancer, in general includes, but is not limited to, spontaneously occurring tumors of companion animals (see, e.g., Vail & MacEwen, 2000, Cancer Invest 18(8):781-92). Examples of animal models for lung cancer include, but are not limited to, lung cancer animal models described by Zhang & Roth (1994, In Vivo 8(5):755-69) and a transgenic mouse model with disrupted p53 function (see, e.g., Morris et al., 1998, J La State Med Soc 150(4):179-85). An example of an animal model for breast cancer includes, but is not limited to, a transgenic mouse that overexpresses cyclin D1 (see, e.g., Hosokawa et al., 2001, Transgenic Res 10(5):471-8). An example of an animal model for colon cancer includes, but is not limited to, a TCRbeta and p53 double knockout mouse (see, e.g., Kado et al., 2001, Cancer Res 61(6):2395-8). Examples of animal models for pancreatic cancer include, but are not limited to, a metastatic model of Panc02 murine pancreatic adenocarcinoma (see, e.g., Wang et al., 2001, Int J Pancreatol 29(1):37-46) and nu-nu mice generated in subcutaneous pancreatic tumours (see, e.g., Ghaneh et al., 2001, Gene Ther 8(3):199-208). Examples of animal models for non-Hodgkin's lymphoma include, but are not limited to, a severe combined immunodeficiency (“SCID”) mouse (see, e.g., Bryant et al., 2000, Lab Invest 80(4):553-73) and an IgHmu-HOX11 transgenic mouse (see, e.g., Hough et al., 1998, Proc Natl Acad Sci USA 95(23):13853-8). An example of an animal model for esophageal cancer includes, but is not limited to, a mouse transgenic for the human papillomavirus type 16 E7 oncogene (see, e.g., Herber et al., 1996, J Virol 70(3):1873-81). Examples of animal models for colorectal carcinomas include, but are not limited to, Apc mouse models (see, e.g., Fodde & Smits, 2001, Trends Mol Med 7(8):369-73 and Kuraguchi et al., 2000, Oncogene 19(50):5755-63). An example of an animal model for neurofibromatosis includes, but is not limited to, mutant NF1 mice (see, e.g., Cichowski et al., 1996, Semin Cancer Biol 7(5):291-8). Examples of animal models for retinoblastoma include, but are not limited to, transgenic mice that expression the simian virus 40 T antigen in the retina (see, e.g., Howes et al., 1994, Invest Ophthalmol Vis Sci 35(2):342-51 and Windle et al, 1990, Nature 343(6259):665-9) and inbred rats (see, e.g., Nishida et al., 1981, Curr Eye Res 1(1):53-5 and Kobayashi et al., 1982, Acta Neuropathol (Berl) 57(2-3):203-8). Examples of animal models for Wilm's tumor include, but are not limited to, a WT1 knockout mice (see, e.g., Schamhorst et al., 1997, Cell Growth Differ 8(2):133-43), a rat subline with a high incidence of neuphroblastoma (see, e.g., Mesfin & Breech, 1996, Lab Anim Sci 46(3):321-6), and a Wistar/Furth rat with Wilms' tumor (see, e.g., Murphy et al., 1987, Anticancer Res 7(4B):717-9).

Retinitis Pigmentosa

Examples of animal models for retinitis pigmentosa include, but are not limited to, the Royal College of Surgeons (“RCS”) rat (see, e.g., Vollrath et al., 2001, Proc Natl Acad Sci USA 98(22); 12584-9 and Hanitzsch et al., 1998, Acta Anat (Basel) 162(2-3):119-26), a rhodopsin knockout mouse (see, e.g., Jaissle et al., 2001, Invest Ophthalmol Vis Sci 42(2):506-13), and Wag/Rij rats (see, e.g., Lai et al., 1980, Am J Pathol 98(1):281-4).

Cirrhosis

Examples of animal models for cirrhosis include, but are not limited to, CCl₄-exposed rats (see, e.g., Kloehn et al., 2001, Horm Metab Res 33(7):394-401) and rodent models instigated by bacterial cell components or colitis (see, e.g., Vierling, 2001, Best Pract Res Clin Gastroenterol 15(4):591-610).

Hemophilia

Examples of animal models for hemophilia include, but are not limited to, rodent models for hemophilia A (see, e.g., Reipert et al., 2000, Thromb Haemost 84(5):826-32; Jarvis et al., 1996, Thromb Haemost 75(2):318-25; and Bi et al., 1995, Nat Genet 10(1):119-21), canine models for hemophilia A (see, e.g., Gallo-Penn et al., 1999, Hum Gene Ther 10(11):1791-802 and Connelly et al, 1998, Blood 91(9); 3273-81), murine models for hemophilia B (see, e.g., Snyder et al., 1999, Nat Med 5(1):64-70; Wang et al., 1997, Proc Natl Acad Sci USA 94(21):11563-6; and Fang et al., 1996, Gene Ther 3(3):217-22), canine models for hemophilia B (see, e.g., Mount et al., 2002, Blood 99(8):2670-6; Snyder et al., 1999, Nat Med 5(1):64-70; Fang et al., 1996, Gene Ther 3(3):217-22); and Kay et al., 1994, Proc Natl Acad Sci USA 91(6):2353-7), and a rhesus macaque model for hemophilia B (see, e.g., Lozier et al., 1999, Blood 93(6):1875-81).

von Willebrand Disease

Examples of animal models for von Willebrand disease include, but are not limited to, an inbred mouse strain RIIIS/J (see, e.g., Nichols et al., 1994, 83(11):3225-31 and Sweeney et al., 1990, 76(11):2258-65), rats injected with botrocetin (see, e.g., Sanders et al., 1988, Lab Invest 59(4):443-52), and porcine models for von Willebrand disease (see, e.g., Nichols et al., 1995, Proc Natl Acad Sci USA 92(7):2455-9; Johnson & Bowie, 1992, J Lab Clin Med 120(4):553-8); and Brinkhous et al., 1991, Mayo Clin Proc 66(7):733-42).

β-Thalassemia

Examples of animal models for β-thalassemia include, but are not limited to, murine models with mutations in globin genes (see, e.g., Lewis et al., 1998, Blood 91(6):2152-6; Raja et al., 1994, Br J Haematol 86(1):156-62; Popp et al., 1985, 445:432-44; and Skow et al., 1983, Cell 34(3): 1043-52).

Kidney Stones

Examples of animal models for kidney stones include, but are not limited to, genetic hypercalciuric rats (see, e.g., Bushinsky et al., 1999, Kidney Int 55(1):234-43 and Bushinsky et al., 1995, Kidney Int 48(6):1705-13), chemically treated rats (see, e.g., Grases et al., 1998, Scand J Urol Nephrol 32(4):261-5; Burgess et al., 1995, Urol Res 23(4):239-42; Kumar et al., 1991, J Urol 146(5):1384-9; Okada et al., 1985, Hinyokika Kiyo 31(4):565-77; and Bluestone et al., 1975, Lab Invest 33(3):273-9), hyperoxaluric rats (see, e.g., Jones et al., 1991, J Urol 145(4):868-74), pigs with unilateral retrograde flexible nephroscopy (see, e.g., Seifmah et al., 2001, 57(4):832-6), and rabbits with an obstructed upper urinary tract (see, e.g., Itatani et al., 1979, Invest Urol 17(3):234-40).

Ataxia-Telangiectasia

Examples of animal models for ataxia-telangiectasia include, but are not limited to, murine models of ataxia-telangiectasia (see, e.g., Barlow et al., 1999, Proc Natl Acad Sci USA 96(17):9915-9 and Inoue et al., 1986, Cancer Res 46(8):3979-82),

Lysosomal Storage Diseases

Examples of animal models for lysosomal storage diseases include, but are not limited to, mouse models for mucopolysaccharidosis type VII (see, e.g., Brooks et al., 2002, Proc Natl Acad Sci USA. 99(9):6216-21; Monroy et al., 2002, Bone 30(2):352-9; Vogler et al., 2001, Pediatr Dev Pathol. 4(5):421-33; Vogler et al., 2001, Pediatr Res. 49(3):342-8; and Wolfe et al., 2000, Mol Ther. 2(6):552-6), a mouse model for metachromatic leukodystrophy (see, e.g., Matzner et al., 2002, Gene Ther. 9(1):53-63), a mouse model of Sandhoff disease (see, e.g., Sango et al., 2002, Neuropathol Appl Neurobiol. 28(1):23-34), mouse models for mucopolysaccharidosis type III A (see, e.g., Bhattacharyya et al., 2001, Glycobiology 11(1):99-10 and Bhaumik et al., 1999, Glycobiology 9(12): 1389-96.), arylsulfatase A (ASA)-deficient mice (see, e.g., D'Hooge et al., 1999, Brain Res. 847(2):352-6 and D'Hooge et al, 1999, Neurosci Lett. 273(2):93-6); mice with an aspartylglucosaminuria mutation (see, e.g., Jalanko et al., 1998, Hum Mol Genet. 7(2):265-72); feline models of mucopolysaccharidosis type VI (see, e.g., Crawley et al., 1998, J Clin Invest. 101(1):109-19 and Norrdin et al., 1995, Bone 17(5):485-9); a feline model of Niemann-Pick disease type C (see, e.g., March et al., 1997, Acta Neuropathol (Berl). 94(2):164-72); acid sphingomyelinase-deficient mice (see, e.g., Otterbach & Stoffel, 1995, Cell 81(7):1053-6), and bovine mannosidosis (see, e.g., Jolly et al., 1975, Birth Defects Orig Arctic Ser. 11(6):273-8).

Tuberous Sclerosis

Examples of animal models for tuberous sclerosis (“TSC”) include, but are not limited to, a mouse model of TSC1 (see, e.g., Kwiatkowski et al., 2002, Hum Mol Genet. 11(5):525-34), a Tsc1 (TSC1 homologue) knockout mouse (see, e.g., Kobayashi et al., 2001, Proc Nail Acad Sci USA. 2001 Jul. 17; 98(15):8762-7), a TSC2 gene mutant(Eker) rat model (see, e.g., Hino 2000, Nippon Rinsho 58(6):1255-61; Mizuguchi et al., 2000, J Neuropathol Exp Neurol. 59(3):188-9; and Hino et al., 1999, Prog Exp Tumor Res. 35:95-108); and Tsc2(+/−) mice (see, e.g., Onda et al., 1999, J Clin Invest. 104(6):687-95).

Example 5 Mdx Mouse, an Animal Model Study

The mutation in the mdx mouse that causes premature translation termination of the 427 kDa dystrophin polypeptide has been shown to be a C to T transition at position 3185 in exon 23 (Sicinski et al., Science 244(4912):1578-1580 (1989)). Mouse primary skeletal muscle cultures derived from 1-day old mdx mice are prepared as described previously (Barton-Davis et al., J. Clin. Invest. 104(4):375-381 (1999)). Cells are cultured for 10 days in the presence of a compound of the invention. Culture medium is replaced every four days and the presence of dystrophin in myoblast cultures is detected by immunostaining as described previously (Barton-Davis et al., J. Clin. Invest. 104(4):375-381 (1999), hereby incorporated by reference in its entirety). A primary monoclonal antibody to the C-terminus of the dystrophin protein is used undiluted and rhodamine conjugated anti-mouse IgG is used as the secondary antibody. The antibody detects the full-length protein produced by suppression of the nonsense codon. Staining is viewed using a Leica DMR microscope, digital camera, and associated imaging software.

As previously described (Barton-Davis et al., J. Clin. Invest. 104(4):375-381 (1999), a compound is delivered by Alzet osmotic pumps implanted under the skin of anesthetized mice. Two doses of a compound of the invention are administered. Gentamicin serves as a positive control and pumps filled with solvent serve as the negative control. Pumps are loaded with appropriate compound such that the calculated doses to which tissue is exposed are 10 mM and 20 mM. The gentamicin concentration is calculated to achieve tissue exposure of approximately 200 mM. In the initial experiment, mice are treated for 14 days, after which animals are anesthetized with ketamine and exsanguinated. The tibialis anterior (TA) muscle of the experimental animals is then excised, frozen, and used for immunofluorescence analysis of dystrophin incorporation into striated muscle. The presence of dystrophin in TA muscles is detected by immunostaining, as described previously (Barton-Davis et al., J. Clin. Invest. 104(4):375-381 (1999).

Western Blot Analysis

Quadricep muscles from an mdx mouse treated with a compound of the present invention for 4 weeks are analyzed by Western blot using a commercially available antibody to dystrophin. Protein extracted from the quadriceps of a wild-type mouse serve as a positive control. Production of full-length dystrophin is observed in the treated animal. The amount of full-length dystrophin produced, as a result of nonsense suppression, but not limited by this theory, is approximately 10% of wild-type levels of expression.

Immunofluorescence

Male mdx mice (age 9-11 weeks) are treated with different compounds of the present invention (n=2 at least for each compound). These compounds are injected SQ once per day for two weeks at 25 mg/kg. After 2 weeks of treatment, mice are sacrificed for the removal of muscles to determine dystrophin readthrough efficiency.

Immunofluorescence (IF) is performed on 10 μm cryosections using a dystrophin antibody. The antibody recognizes an epitope C-terminal to the premature stop mutation found in mdx mice. Image analysis is performed in an identical manner in all sections. Images from treated and untreated mice are analyzed and a signal greater than the signal on the untreated control is deemed positive and indicates that suppression of the premature termination codon in the dystrophin mRNA occurred.

Muscle Mechanics

Isolated whole muscle mechanics is performed on EDL muscles from animals. Optimum muscle length (Lo) is defined as the length that produced maximum twitch tension. Maximum tetanic force at Lo is measured using a 120 Hz, 500 msec pulse at supramaximal voltage. Protection against mechanical injury, induced by a series of 5 eccentric tetanic contractions, is monitored. These measurements are performed using a 700 msec stimulation period during which the muscle is held in an isometric contraction for the first 500 msec followed by a stretch of 8 or 10% Lo at a rate of 0.5 Lo/sec. Protection against mechanical injury is evaluated at 80 Hz stimulation frequency. Damage is determined as the loss in force between the first and last eccentric contraction. Treatment with compounds of the present invention result in protection from damage induced by eccentric contractions of the EDL muscle compared to the untreated control.

Example 6 Suppression of a Nonsense Mutation in the p53 Gene

For an animal model system, CAOV-3 cells (1×10⁷) are injected into the flanks of nude/nude mice. After 12 days, mice are randomized (10 mice per group) and treated subcutaneously (5 days per week) with 3 mg/kg of a compound of the present invention or intraperitonealy (1 day per week) with 30 mg/kg of a compound of the present invention. Tumor volumes are measured weekly. Suppression of nonsense mutations in the p53 gene by a compound of the present invention can inhibit cancer growth in vivo.

Example 7 Access to Specific Nucleotides of the 28S rRNA is Modified by Compounds of the Present Invention

Previous studies have demonstrated that gentamicin and other members of the aminoglycoside family that decrease the fidelity of translation bind to the A site of the 16S rRNA. By chemical footprinting, UV cross-linking and NMR, gentamicin has been shown to bind at the A site (comprised of nucleotides 1400-1410 and 1490-1500, E. coli numbering) of the rRNA at nucleotides 1406, 1407, 1494, and 1496 (Moazed & Noller, Nature 327(6121):389-394 (1978); Woodcock et al., EMBO J. 10(10):3099-3103 (1991); and Schroeder et al., EMBO J. 19:1-9 (2000).

Ribosomes prepared from HeLa cells are incubated with the small molecules (at a concentration of 100 mM), followed by treatment with chemical modifying agents (dimethyl sulfate [DMS] and kethoxal [KE]). Following chemical modification, rRNA is phenol-chloroform extracted, ethanol precipitated, analyzed in primer extension reactions using end-labeled oligonucleotides hybridizing to different regions of the three rRNAs and resolved on 6% polyacrylamide gels. Probes for primer extension cover the entire 18S (7 oligonucleotide primers), 28S (24 oligonucleotide primers), and 5S (one primer) rRNAs. Controls in these experiments include DMSO (a control for changes in rRNA accessibility induced by DMSO), paromomycin (a marker for 18S rRNA binding), and anisomycin (a marker for 28S rRNA binding).

All publications and patent applications cited herein are incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

Although certain embodiments have been described in detail above, those having ordinary skill in the art will clearly understand that many modifications are possible in the embodiments without departing from the teachings thereof. All such modifications are intended to be encompassed within the claims of the invention. 

What is claimed:
 1. A method of treating cystic fibrosis resulting from a genetic or somatic nonsense mutation in a patient in need thereof comprising administering to the patient a compound selected from the group consisting of:

and a pharmaceutically acceptable salt, racemate or stereoisomer thereof.
 2. The method of claim 1, wherein the compound, or a pharmaceutically acceptable salt, racemate or stereoisomer thereof, is administered as a composition comprising the compound and a pharmaceutically acceptable carrier or diluent.
 3. The method of claim 1, wherein the administration is intravenous. 